Class FormLayout

  • All Implemented Interfaces:
    java.awt.LayoutManager, java.awt.LayoutManager2, java.io.Serializable

    public final class FormLayout
    extends java.lang.Object
    implements java.awt.LayoutManager2, java.io.Serializable
    FormLayout is a powerful, flexible and precise general purpose layout manager. It aligns components vertically and horizontally in a dynamic rectangular grid of cells, with each component occupying one or more cells. A whitepaper about the FormLayout ships with the product documentation and is available online.

    To use FormLayout you first define the grid by specifying the columns and rows. In a second step you add components to the grid. You can specify columns and rows via human-readable String descriptions or via arrays of ColumnSpec and RowSpec instances.

    Each component managed by a FormLayout is associated with an instance of CellConstraints. The constraints object specifies where a component should be located on the form's grid and how the component should be positioned. In addition to its constraints object the FormLayout also considers each component's minimum and preferred sizes in order to determine a component's size.

    FormLayout has been designed to work with non-visual builders that help you specify the layout and fill the grid. For example, the ButtonBarBuilder assists you in building button bars; it creates a standardized FormLayout and provides a minimal API that specializes in adding buttons and Actions. Other builders can create frequently used panel design, for example a form that consists of rows of label-component pairs.

    FormLayout has been prepared to work with different types of sizes as defined by the Size interface.

    Example 1 (Plain FormLayout):
    The following example creates a panel with 3 data columns and 3 data rows; the columns and rows are specified before components are added to the form.

     FormLayout layout = new FormLayout(
          "right:pref, 6dlu, 50dlu, 4dlu, default",  // columns
          "pref, 3dlu, pref, 3dlu, pref");           // rows
    
     JPanel panel = new JPanel(layout);
     panel.add(new JLabel("Label1"),   CC.xy  (1, 1));
     panel.add(new JTextField(),       CC.xywh(3, 1, 3, 1));
     panel.add(new JLabel("Label2"),   CC.xy  (1, 3));
     panel.add(new JTextField(),       CC.xy  (3, 3));
     panel.add(new JLabel("Label3"),   CC.xy  (1, 5));
     panel.add(new JTextField(),       CC.xy  (3, 5));
     panel.add(new JButton("/u2026"),  CC.xy  (5, 5));
     return panel;
     

    Example 2 (Using PanelBuilder):
    This example creates the same panel as above using the PanelBuilder to add components to the form.

     FormLayout layout = new FormLayout(
          "right:pref, 6dlu, 50dlu, 4dlu, default",  // columns
          "pref, 3dlu, pref, 3dlu, pref");           // rows
    
     PanelBuilder builder = new PanelBuilder(layout);
     builder.addLabel("Label1",         CC.xy  (1, 1));
     builder.add(new JTextField(),      CC.xywh(3, 1, 3, 1));
     builder.addLabel("Label2",         CC.xy  (1, 3));
     builder.add(new JTextField(),      CC.xy  (3, 3));
     builder.addLabel("Label3",         CC.xy  (1, 5));
     builder.add(new JTextField(),      CC.xy  (3, 5));
     builder.add(new JButton("/u2026"), CC.xy  (5, 5));
     return builder.getPanel();
     

    Example 3 (Using DefaultFormBuilder):
    This example utilizes the DefaultFormBuilder that ships with the source distribution.

     FormLayout layout = new FormLayout(
          "right:pref, 6dlu, 50dlu, 4dlu, default"); // 5 columns; add rows later
    
     DefaultFormBuilder builder = new DefaultFormBuilder(layout);
     builder.append("Label1", new JTextField(), 3);
     builder.append("Label2", new JTextField());
     builder.append("Label3", new JTextField());
     builder.append(new JButton("/u2026"));
     return builder.getPanel();
     
    Version:
    $Revision: 1.30 $
    See Also:
    ColumnSpec, RowSpec, CellConstraints, AbstractFormBuilder, ButtonBarBuilder, DefaultFormBuilder, FormSpecs, Size, Sizes, Serialized Form
    • Constructor Summary

      Constructors 
      Constructor Description
      FormLayout()
      Constructs an empty FormLayout.
      FormLayout​(ColumnSpec[] colSpecs)
      Constructs a FormLayout using the given column specifications.
      FormLayout​(ColumnSpec[] colSpecs, RowSpec[] rowSpecs)
      Constructs a FormLayout using the given column and row specifications.
      FormLayout​(java.lang.String encodedColumnSpecs)
      Constructs a FormLayout using the given encoded column specifications.
      FormLayout​(java.lang.String encodedColumnSpecs, LayoutMap layoutMap)
      Constructs a FormLayout using the given encoded column specifications and LayoutMap.
      FormLayout​(java.lang.String encodedColumnSpecs, java.lang.String encodedRowSpecs)
      Constructs a FormLayout using the given encoded column and row specifications and the default LayoutMap.
      FormLayout​(java.lang.String encodedColumnSpecs, java.lang.String encodedRowSpecs, LayoutMap layoutMap)
      Constructs a FormLayout using the given encoded column and row specifications and the given LayoutMap.
    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void addGroupedColumn​(int columnIndex)
      Adds the specified column index to the last column group.
      void addGroupedRow​(int rowIndex)
      Adds the specified row index to the last row group.
      void addLayoutComponent​(java.awt.Component comp, java.lang.Object constraints)
      Adds the specified component to the layout, using the specified constraints object.
      void addLayoutComponent​(java.lang.String name, java.awt.Component component)
      Throws an UnsupportedOperationException.
      private static void adjustGroupIndices​(int[][] allGroupIndices, int modifiedIndex, boolean remove)
      Adjusts group indices.
      void appendColumn​(ColumnSpec columnSpec)
      Appends the given column specification to the right hand side of all columns.
      void appendRow​(RowSpec rowSpec)
      Appends the given row specification to the bottom of all rows.
      private static int[] compressedSizes​(java.util.List formSpecs, int totalSize, int totalMinSize, int totalPrefSize, int[] minSizes, int[] prefSizes)
      Computes and returns the compressed sizes.
      private static int[] computeGridOrigins​(java.awt.Container container, int totalSize, int offset, java.util.List formSpecs, java.util.List[] componentLists, int[][] groupIndices, FormLayout.Measure minMeasure, FormLayout.Measure prefMeasure)
      Computes and returns the grid's origins.
      private java.awt.Dimension computeLayoutSize​(java.awt.Container parent, FormLayout.Measure defaultWidthMeasure, FormLayout.Measure defaultHeightMeasure)
      Computes and returns the layout size of the given parent container using the specified measures.
      private static int[] computeMaximumFixedSpanTable​(java.util.List formSpecs)
      Computes and returns a table that maps a column/row index to the maximum number of columns/rows that a component can span without spanning a growing column.
      private static int[] computeOrigins​(int[] sizes, int offset)
      Computes origins from sizes taking the specified offset into account.
      private static int[][] deepClone​(int[][] array)
      Creates and returns a deep copy of the given array.
      private static int[] distributedSizes​(java.util.List formSpecs, int totalSize, int totalPrefSize, int[] inputSizes)
      Distributes free space over columns and rows and returns the sizes after this distribution process.
      int getColumnCount()
      Returns the number of columns in this layout.
      int[][] getColumnGroups()
      Returns a deep copy of the column groups.
      ColumnSpec getColumnSpec​(int columnIndex)
      Returns the ColumnSpec at the specified column index.
      CellConstraints getConstraints​(java.awt.Component component)
      Looks up and returns the constraints for the specified component.
      private CellConstraints getConstraints0​(java.awt.Component component)  
      boolean getHonorsVisibility()
      Returns whether invisible components shall be taken into account by this layout.
      float getLayoutAlignmentX​(java.awt.Container parent)
      Returns the alignment along the x axis.
      float getLayoutAlignmentY​(java.awt.Container parent)
      Returns the alignment along the y axis.
      FormLayout.LayoutInfo getLayoutInfo​(java.awt.Container parent)
      Computes and returns the horizontal and vertical grid origins.
      int getRowCount()
      Returns the number of rows in this layout.
      int[][] getRowGroups()
      Returns a deep copy of the row groups.
      RowSpec getRowSpec​(int rowIndex)
      Returns the RowSpec at the specified row index.
      private static int[] groupedSizes​(int[][] groups, int[] rawSizes)
      Computes and returns the grouped sizes.
      private void initializeColAndRowComponentLists()
      Initializes two lists for columns and rows that hold a column's or row's components that span only this column or row.
      void insertColumn​(int columnIndex, ColumnSpec columnSpec)
      Inserts the specified column at the specified position.
      void insertRow​(int rowIndex, RowSpec rowSpec)
      Inserts the specified column at the specified position.
      private static void invalidateAndRepaint​(java.awt.Container container)  
      private void invalidateCaches()
      Invalidates the component size caches.
      void invalidateLayout​(java.awt.Container target)
      Invalidates the layout, indicating that if the layout manager has cached information it should be discarded.
      private void layoutComponents​(int[] x, int[] y)
      Lays out the components using the given x and y origins, the column and row specifications, and the component constraints.
      void layoutContainer​(java.awt.Container parent)
      Lays out the specified container using this form layout.
      java.awt.Dimension maximumLayoutSize​(java.awt.Container target)
      Returns the maximum dimensions for this layout given the components in the specified target container.
      private static int[] maximumSizes​(java.awt.Container container, java.util.List formSpecs, java.util.List[] componentLists, FormLayout.Measure minMeasure, FormLayout.Measure prefMeasure, FormLayout.Measure defaultMeasure)
      Computes and returns the sizes for the given form specs, component lists and measures for minimum, preferred, and default size.
      java.awt.Dimension minimumLayoutSize​(java.awt.Container parent)
      Determines the minimum size of the parent container using this form layout.
      java.awt.Dimension preferredLayoutSize​(java.awt.Container parent)
      Determines the preferred size of the parent container using this form layout.
      void removeColumn​(int columnIndex)
      Removes the column with the given column index from the layout.
      private void removeConstraints​(java.awt.Component component)
      Removes the constraints for the specified component in this layout.
      void removeLayoutComponent​(java.awt.Component comp)
      Removes the specified component from this layout.
      void removeRow​(int rowIndex)
      Removes the row with the given row index from the layout.
      void setColumnGroup​(int... indices)
      Sets a single column group, where each column gets the same width.
      void setColumnGroups​(int[][] groupOfIndices)
      Sets the column groups, where each column in a group gets the same group wide width.
      private void setColumnGroupsImpl​(int[][] groupOfIndices, boolean checkIndices)  
      void setColumnSpec​(int columnIndex, ColumnSpec columnSpec)
      Sets the ColumnSpec at the specified column index.
      void setConstraints​(java.awt.Component component, CellConstraints constraints)
      Sets the constraints for the specified component in this layout.
      void setHonorsVisibility​(boolean b)
      Specifies whether invisible components shall be taken into account by this layout for computing the layout size and setting component bounds.
      void setHonorsVisibility​(java.awt.Component component, java.lang.Boolean b)
      Specifies whether the given component shall be taken into account for sizing and positioning.
      void setRowGroup​(int... indices)
      Sets a single row group, where each row gets the same height.
      void setRowGroups​(int[][] groupOfIndices)
      Sets the row groups, where each row in such a group gets the same group wide height.
      private void setRowGroupsImpl​(int[][] groupOfIndices, boolean checkIndices)  
      void setRowSpec​(int rowIndex, RowSpec rowSpec)
      Sets the RowSpec at the specified row index.
      private void shiftComponentsHorizontally​(int columnIndex, boolean remove)
      Shifts components horizontally, either to the right if a column has been inserted or to the left if a column has been removed.
      private void shiftComponentsVertically​(int rowIndex, boolean remove)
      Shifts components vertically, either to the bottom if a row has been inserted or to the top if a row has been removed.
      private static int sum​(int[] sizes)
      Computes and returns the sum of integers in the given array of ints.
      private boolean takeIntoAccount​(java.awt.Component component, CellConstraints cc)
      Checks and answers whether the given component with the specified CellConstraints shall be taken into account for the layout.
      private void writeObject​(java.io.ObjectOutputStream out)
      In addition to the default serialization mechanism this class invalidates the component size cache.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Constructor Detail

      • FormLayout

        public FormLayout()
        Constructs an empty FormLayout. Columns and rows must be added before components can be added to the layout container.

        This constructor is intended to be used in environments that add columns and rows dynamically.

      • FormLayout

        public FormLayout​(java.lang.String encodedColumnSpecs)
        Constructs a FormLayout using the given encoded column specifications. The constructed layout has no rows; these must be added before components can be added to the layout container. The string decoding uses the default LayoutMap.

        This constructor is intended to be used with builder classes that add rows dynamically, such as the DefaultFormBuilder.

        Examples:

         // Label, gap, component
         FormLayout layout = new FormLayout(
              "pref, 4dlu, pref");
        
         // Right-aligned label, gap, component, gap, component
         FormLayout layout = new FormLayout(
              "right:pref, 4dlu, 50dlu, 4dlu, 50dlu");
        
         // Left-aligned labels, gap, components, gap, components
         FormLayout layout = new FormLayout(
              "left:pref, 4dlu, pref, 4dlu, pref");
         
        See the class comment for more examples.
        Parameters:
        encodedColumnSpecs - comma separated encoded column specifications
        Throws:
        java.lang.NullPointerException - if encodedColumnSpecs is null
        See Also:
        LayoutMap.getRoot()
      • FormLayout

        public FormLayout​(java.lang.String encodedColumnSpecs,
                          LayoutMap layoutMap)
        Constructs a FormLayout using the given encoded column specifications and LayoutMap. The constructed layout has no rows; these must be added before components can be added to the layout container.

        This constructor is intended to be used with builder classes that add rows dynamically, such as the DefaultFormBuilder.

        Examples:

         // Label, gap, component
         FormLayout layout = new FormLayout(
              "pref, 4dlu, pref",
              myLayoutMap);
        
         // Right-aligned label, gap, component, gap, component
         FormLayout layout = new FormLayout(
              "right:pref, @lcgap, 50dlu, 4dlu, 50dlu",
              myLayoutMap);
        
         // Left-aligned labels, gap, components, gap, components
         FormLayout layout = new FormLayout(
              "left:pref, @lcgap, pref, @myGap, pref",
              myLayoutMap);
         
        See the class comment for more examples.
        Parameters:
        encodedColumnSpecs - comma separated encoded column specifications
        layoutMap - expands layout column and row variables
        Throws:
        java.lang.NullPointerException - if encodedColumnSpecs or layoutMap is null
        Since:
        1.2
        See Also:
        LayoutMap.getRoot()
      • FormLayout

        public FormLayout​(java.lang.String encodedColumnSpecs,
                          java.lang.String encodedRowSpecs)
        Constructs a FormLayout using the given encoded column and row specifications and the default LayoutMap.

        This constructor is recommended for most hand-coded layouts.

        Examples:

         FormLayout layout = new FormLayout(
              "pref, 4dlu, pref",               // columns
              "p, 3dlu, p");                    // rows
        
         FormLayout layout = new FormLayout(
              "right:pref, 4dlu, pref",         // columns
              "p, 3dlu, p, 3dlu, fill:p:grow"); // rows
        
         FormLayout layout = new FormLayout(
              "left:pref, 4dlu, 50dlu",         // columns
              "p, 2px, p, 3dlu, p, 9dlu, p");   // rows
        
         FormLayout layout = new FormLayout(
              "max(75dlu;pref), 4dlu, default", // columns
              "p, 3dlu, p, 3dlu, p, 3dlu, p");  // rows
         
        See the class comment for more examples.
        Parameters:
        encodedColumnSpecs - comma separated encoded column specifications
        encodedRowSpecs - comma separated encoded row specifications
        Throws:
        java.lang.NullPointerException - if encodedColumnSpecs or encodedRowSpecs is null
        See Also:
        LayoutMap.getRoot()
      • FormLayout

        public FormLayout​(java.lang.String encodedColumnSpecs,
                          java.lang.String encodedRowSpecs,
                          LayoutMap layoutMap)
        Constructs a FormLayout using the given encoded column and row specifications and the given LayoutMap.

        Examples:

         FormLayout layout = new FormLayout(
              "pref, 4dlu, pref",               // columns
              "p, 3dlu, p",                     // rows
              myLayoutMap);                     // custom LayoutMap
        
         FormLayout layout = new FormLayout(
              "right:pref, 4dlu, pref",         // columns
              "p, @lgap, p, @lgap, fill:p:grow",// rows
              myLayoutMap);                     // custom LayoutMap
        
         FormLayout layout = new FormLayout(
              "left:pref, 4dlu, 50dlu",         // columns
              "p, 2px, p, 3dlu, p, 9dlu, p",    // rows
              myLayoutMap);                     // custom LayoutMap
        
         FormLayout layout = new FormLayout(
              "max(75dlu;pref), 4dlu, default", // columns
              "p, 3dlu, p, 3dlu, p, 3dlu, p",   // rows
              myLayoutMap);                     // custom LayoutMap
         
        See the class comment for more examples.
        Parameters:
        encodedColumnSpecs - comma separated encoded column specifications
        encodedRowSpecs - comma separated encoded row specifications
        layoutMap - expands layout column and row variables
        Throws:
        java.lang.NullPointerException - if encodedColumnSpecs, encodedRowSpecs, or layoutMap is null
        Since:
        1.2
      • FormLayout

        public FormLayout​(ColumnSpec[] colSpecs)
        Constructs a FormLayout using the given column specifications. The constructed layout has no rows; these must be added before components can be added to the layout container.
        Parameters:
        colSpecs - an array of column specifications.
        Throws:
        java.lang.NullPointerException - if colSpecs is null
        Since:
        1.1
      • FormLayout

        public FormLayout​(ColumnSpec[] colSpecs,
                          RowSpec[] rowSpecs)
        Constructs a FormLayout using the given column and row specifications.
        Parameters:
        colSpecs - an array of column specifications.
        rowSpecs - an array of row specifications.
        Throws:
        java.lang.NullPointerException - if colSpecs or rowSpecs is null
    • Method Detail

      • getColumnCount

        public int getColumnCount()
        Returns the number of columns in this layout.
        Returns:
        the number of columns
      • getColumnSpec

        public ColumnSpec getColumnSpec​(int columnIndex)
        Returns the ColumnSpec at the specified column index.
        Parameters:
        columnIndex - the column index of the requested ColumnSpec
        Returns:
        the ColumnSpec at the specified column
        Throws:
        java.lang.IndexOutOfBoundsException - if the column index is out of range
      • setColumnSpec

        public void setColumnSpec​(int columnIndex,
                                  ColumnSpec columnSpec)
        Sets the ColumnSpec at the specified column index.
        Parameters:
        columnIndex - the index of the column to be changed
        columnSpec - the ColumnSpec to be set
        Throws:
        java.lang.NullPointerException - if columnSpec is null
        java.lang.IndexOutOfBoundsException - if the column index is out of range
      • appendColumn

        public void appendColumn​(ColumnSpec columnSpec)
        Appends the given column specification to the right hand side of all columns.
        Parameters:
        columnSpec - the column specification to be added
        Throws:
        java.lang.NullPointerException - if columnSpec is null
      • insertColumn

        public void insertColumn​(int columnIndex,
                                 ColumnSpec columnSpec)
        Inserts the specified column at the specified position. Shifts components that intersect the new column to the right hand side and readjusts column groups.

        The component shift works as follows: components that were located on the right hand side of the inserted column are shifted one column to the right; component column span is increased by one if it intersects the new column.

        Column group indices that are greater or equal than the given column index will be increased by one.

        Parameters:
        columnIndex - index of the column to be inserted
        columnSpec - specification of the column to be inserted
        Throws:
        java.lang.IndexOutOfBoundsException - if the column index is out of range
      • removeColumn

        public void removeColumn​(int columnIndex)
        Removes the column with the given column index from the layout. Components will be rearranged and column groups will be readjusted. Therefore, the column must not contain components and must not be part of a column group.

        The component shift works as follows: components that were located on the right hand side of the removed column are moved one column to the left; component column span is decreased by one if it intersects the removed column.

        Column group indices that are greater than the column index will be decreased by one.

        Note: If one of the constraints mentioned above is violated, this layout's state becomes illegal and it is unsafe to work with this layout. A typical layout implementation can ensure that these constraints are not violated. However, in some cases you may need to check these conditions before you invoke this method. The Forms extras contain source code for class FormLayoutUtils that provides the required test methods:
        #columnContainsComponents(Container, int) and
        #isGroupedColumn(FormLayout, int).

        Parameters:
        columnIndex - index of the column to remove
        Throws:
        java.lang.IndexOutOfBoundsException - if the column index is out of range
        java.lang.IllegalStateException - if the column contains components or if the column is already grouped
        See Also:
        FormLayoutUtils.columnContainsComponent(Container, int), FormLayoutUtils.isGroupedColumn(FormLayout, int)
      • getRowCount

        public int getRowCount()
        Returns the number of rows in this layout.
        Returns:
        the number of rows
      • getRowSpec

        public RowSpec getRowSpec​(int rowIndex)
        Returns the RowSpec at the specified row index.
        Parameters:
        rowIndex - the row index of the requested RowSpec
        Returns:
        the RowSpec at the specified row
        Throws:
        java.lang.IndexOutOfBoundsException - if the row index is out of range
      • setRowSpec

        public void setRowSpec​(int rowIndex,
                               RowSpec rowSpec)
        Sets the RowSpec at the specified row index.
        Parameters:
        rowIndex - the index of the row to be changed
        rowSpec - the RowSpec to be set
        Throws:
        java.lang.NullPointerException - if rowSpec is null
        java.lang.IndexOutOfBoundsException - if the row index is out of range
      • appendRow

        public void appendRow​(RowSpec rowSpec)
        Appends the given row specification to the bottom of all rows.
        Parameters:
        rowSpec - the row specification to be added to the form layout
        Throws:
        java.lang.NullPointerException - if rowSpec is null
      • insertRow

        public void insertRow​(int rowIndex,
                              RowSpec rowSpec)
        Inserts the specified column at the specified position. Shifts components that intersect the new column to the right and readjusts column groups.

        The component shift works as follows: components that were located on the right hand side of the inserted column are shifted one column to the right; component column span is increased by one if it intersects the new column.

        Column group indices that are greater or equal than the given column index will be increased by one.

        Parameters:
        rowIndex - index of the row to be inserted
        rowSpec - specification of the row to be inserted
        Throws:
        java.lang.IndexOutOfBoundsException - if the row index is out of range
      • removeRow

        public void removeRow​(int rowIndex)
        Removes the row with the given row index from the layout. Components will be rearranged and row groups will be readjusted. Therefore, the row must not contain components and must not be part of a row group.

        The component shift works as follows: components that were located below the removed row are moved up one row; component row span is decreased by one if it intersects the removed row.

        Row group indices that are greater than the row index will be decreased by one.

        Note: If one of the constraints mentioned above is violated, this layout's state becomes illegal and it is unsafe to work with this layout. A typical layout implementation can ensure that these constraints are not violated. However, in some cases you may need to check these conditions before you invoke this method. The Forms extras contain source code for class FormLayoutUtils that provides the required test methods:
        #rowContainsComponents(Container, int) and
        #isGroupedRow(FormLayout, int).

        Parameters:
        rowIndex - index of the row to remove
        Throws:
        java.lang.IndexOutOfBoundsException - if the row index is out of range
        java.lang.IllegalStateException - if the row contains components or if the row is already grouped
        See Also:
        FormLayoutUtils.rowContainsComponent(Container, int), FormLayoutUtils.isGroupedRow(FormLayout, int)
      • shiftComponentsHorizontally

        private void shiftComponentsHorizontally​(int columnIndex,
                                                 boolean remove)
        Shifts components horizontally, either to the right if a column has been inserted or to the left if a column has been removed.
        Parameters:
        columnIndex - index of the column to remove
        remove - true for remove, false for insert
        Throws:
        java.lang.IllegalStateException - if a removed column contains components
      • shiftComponentsVertically

        private void shiftComponentsVertically​(int rowIndex,
                                               boolean remove)
        Shifts components vertically, either to the bottom if a row has been inserted or to the top if a row has been removed.
        Parameters:
        rowIndex - index of the row to remove
        remove - true for remove, false for insert
        Throws:
        java.lang.IllegalStateException - if a removed column contains components
      • adjustGroupIndices

        private static void adjustGroupIndices​(int[][] allGroupIndices,
                                               int modifiedIndex,
                                               boolean remove)
        Adjusts group indices. Shifts the given groups to left, right, up, down according to the specified remove or add flag.
        Parameters:
        allGroupIndices - the groups to be adjusted
        modifiedIndex - the modified column or row index
        remove - true for remove, false for add
        Throws:
        java.lang.IllegalStateException - if we remove and the index is grouped
      • getConstraints

        public CellConstraints getConstraints​(java.awt.Component component)
        Looks up and returns the constraints for the specified component. A copy of the actualCellConstraints object is returned.
        Parameters:
        component - the component to be queried
        Returns:
        the CellConstraints for the specified component
        Throws:
        java.lang.NullPointerException - if component is null
        java.lang.IllegalStateException - if component has not been added to the container
      • getConstraints0

        private CellConstraints getConstraints0​(java.awt.Component component)
      • setConstraints

        public void setConstraints​(java.awt.Component component,
                                   CellConstraints constraints)
        Sets the constraints for the specified component in this layout.
        Parameters:
        component - the component to be modified
        constraints - the constraints to be applied
        Throws:
        java.lang.NullPointerException - if component or constraints is null
      • removeConstraints

        private void removeConstraints​(java.awt.Component component)
        Removes the constraints for the specified component in this layout.
        Parameters:
        component - the component to be modified
      • getColumnGroups

        public int[][] getColumnGroups()
        Returns a deep copy of the column groups.
        Returns:
        the column groups as two-dimensional int array
      • setColumnGroups

        public void setColumnGroups​(int[][] groupOfIndices)
        Sets the column groups, where each column in a group gets the same group wide width. Each group is described by an array of integers that are interpreted as column indices. The parameter is an array of such group descriptions.

        Examples:

         // Group columns 1, 3 and 4.
         setColumnGroups(new int[][]{ {1, 3, 4}});
        
         // Group columns 1, 3, 4, and group columns 7 and 9
         setColumnGroups(new int[][]{ {1, 3, 4}, {7, 9}});
         
        Parameters:
        groupOfIndices - a two-dimensional array of column groups indices
        Throws:
        java.lang.IndexOutOfBoundsException - if an index is outside the grid
        java.lang.IllegalArgumentException - if a column index is used twice, or of a group of indices contains only a single element
      • setColumnGroupsImpl

        private void setColumnGroupsImpl​(int[][] groupOfIndices,
                                         boolean checkIndices)
      • setColumnGroup

        public void setColumnGroup​(int... indices)
        Sets a single column group, where each column gets the same width.

        Example:

         // Group columns 1, 3 and 4.
         setColumnGroup(1, 3, 4);
         
        Parameters:
        indices - the indices for a single column group
        Throws:
        java.lang.IndexOutOfBoundsException - if an index is outside the grid
        java.lang.IllegalArgumentException - if a column index is used twice or if there is only a single index
        java.lang.NullPointerException - if indices is null
        Since:
        1.8
        See Also:
        setColumnGroups(int[][])
      • addGroupedColumn

        public void addGroupedColumn​(int columnIndex)
        Adds the specified column index to the last column group. In case there are no groups, a new group will be created.
        Parameters:
        columnIndex - the column index to be set grouped
      • getRowGroups

        public int[][] getRowGroups()
        Returns a deep copy of the row groups.
        Returns:
        the row groups as two-dimensional int array
      • setRowGroups

        public void setRowGroups​(int[][] groupOfIndices)
        Sets the row groups, where each row in such a group gets the same group wide height. Each group is described by an array of integers that are interpreted as row indices. The parameter is an array of such group descriptions.

        Examples:

         // Group rows 1 and 2.
         setRowGroups(new int[][]{ {1, 2}});
        
         // Group rows 1 and 2, and group rows 5, 7, and 9.
         setRowGroups(new int[][]{ {1, 2}, {5, 7, 9}});
         
        Parameters:
        groupOfIndices - a two-dimensional array of row group indices
        Throws:
        java.lang.IndexOutOfBoundsException - if an index is outside the grid
        java.lang.IllegalArgumentException - if a column index is used twice, or of a group of indices contains only a single element
      • setRowGroupsImpl

        private void setRowGroupsImpl​(int[][] groupOfIndices,
                                      boolean checkIndices)
      • setRowGroup

        public void setRowGroup​(int... indices)
        Sets a single row group, where each row gets the same height.

        Example:

         // Group rows 1 and 2.
         setRowGroup(1, 2);
         
        Parameters:
        indices - the indices for a single row group
        Throws:
        java.lang.IndexOutOfBoundsException - if an index is outside the grid
        java.lang.IllegalArgumentException - if a row index is used twice or if there is only a single index
        java.lang.NullPointerException - if indices is null
        Since:
        1.8
        See Also:
        setRowGroups(int[][])
      • addGroupedRow

        public void addGroupedRow​(int rowIndex)
        Adds the specified row index to the last row group. In case there are no groups, a new group will be created.
        Parameters:
        rowIndex - the index of the row that should be grouped
      • getHonorsVisibility

        public boolean getHonorsVisibility()
        Returns whether invisible components shall be taken into account by this layout. This container-wide setting can be overridden per component. See setHonorsVisibility(boolean) for details.
        Returns:
        true if the component visibility is honored by this FormLayout, false if it is ignored. This setting can be overridden for individual CellConstraints using setHonorsVisibility(Component, Boolean).
        Since:
        1.2
      • setHonorsVisibility

        public void setHonorsVisibility​(boolean b)
        Specifies whether invisible components shall be taken into account by this layout for computing the layout size and setting component bounds. If set to true invisible components will be ignored by the layout. If set to false components will be taken into account regardless of their visibility. Visible components are always used for sizing and positioning.

        The default value for this setting is true. It is useful to set the value to false (in other words to ignore the visibility) if you switch the component visibility dynamically and want the container to retain the size and component positions.

        This container-wide default setting can be overridden per component using setHonorsVisibility(Component, Boolean).

        Components are taken into account, if

        1. they are visible, or
        2. they have no individual setting and the container-wide settings ignores the visibility (honorsVisibility set to false), or
        3. the individual component ignores the visibility.
        Parameters:
        b - true to honor the visibility, i.e. to exclude invisible components from the sizing and positioning, false to ignore the visibility, in other words to layout visible and invisible components
        Since:
        1.2
      • setHonorsVisibility

        public void setHonorsVisibility​(java.awt.Component component,
                                        java.lang.Boolean b)
        Specifies whether the given component shall be taken into account for sizing and positioning. This setting overrides the container-wide default. See setHonorsVisibility(boolean) for details.
        Parameters:
        component - the component that shall get an individual setting
        b - Boolean.TRUE to override the container default and honor the visibility for the given component, Boolean.FALSE to override the container default and ignore the visibility for the given component, null to use the container default value as specified by getHonorsVisibility().
        Since:
        1.2
      • addLayoutComponent

        public void addLayoutComponent​(java.lang.String name,
                                       java.awt.Component component)
        Throws an UnsupportedOperationException. Does not add the specified component with the specified name to the layout.
        Specified by:
        addLayoutComponent in interface java.awt.LayoutManager
        Parameters:
        name - indicates entry's position and anchor
        component - component to add
        Throws:
        java.lang.UnsupportedOperationException - always
      • addLayoutComponent

        public void addLayoutComponent​(java.awt.Component comp,
                                       java.lang.Object constraints)
        Adds the specified component to the layout, using the specified constraints object. Note that constraints are mutable and are, therefore, cloned when cached.
        Specified by:
        addLayoutComponent in interface java.awt.LayoutManager2
        Parameters:
        comp - the component to be added
        constraints - the component's cell constraints
        Throws:
        java.lang.NullPointerException - if constraints is null
        java.lang.IllegalArgumentException - if constraints is neither a String, nor a CellConstraints object, or a String that is rejected by the CellConstraints construction
      • removeLayoutComponent

        public void removeLayoutComponent​(java.awt.Component comp)
        Removes the specified component from this layout.

        Most applications do not call this method directly.

        Specified by:
        removeLayoutComponent in interface java.awt.LayoutManager
        Parameters:
        comp - the component to be removed.
        See Also:
        Container.remove(java.awt.Component), Container.removeAll()
      • minimumLayoutSize

        public java.awt.Dimension minimumLayoutSize​(java.awt.Container parent)
        Determines the minimum size of the parent container using this form layout.

        Most applications do not call this method directly.

        Specified by:
        minimumLayoutSize in interface java.awt.LayoutManager
        Parameters:
        parent - the container in which to do the layout
        Returns:
        the minimum size of the parent container
        See Also:
        Container.doLayout()
      • preferredLayoutSize

        public java.awt.Dimension preferredLayoutSize​(java.awt.Container parent)
        Determines the preferred size of the parent container using this form layout.

        Most applications do not call this method directly.

        Specified by:
        preferredLayoutSize in interface java.awt.LayoutManager
        Parameters:
        parent - the container in which to do the layout
        Returns:
        the preferred size of the parent container
        See Also:
        Container.getPreferredSize()
      • maximumLayoutSize

        public java.awt.Dimension maximumLayoutSize​(java.awt.Container target)
        Returns the maximum dimensions for this layout given the components in the specified target container.
        Specified by:
        maximumLayoutSize in interface java.awt.LayoutManager2
        Parameters:
        target - the container which needs to be laid out
        Returns:
        the maximum dimensions for this layout
        See Also:
        Container, minimumLayoutSize(Container), preferredLayoutSize(Container)
      • getLayoutAlignmentX

        public float getLayoutAlignmentX​(java.awt.Container parent)
        Returns the alignment along the x axis. This specifies how the component would like to be aligned relative to other components. The value should be a number between 0 and 1 where 0 represents alignment along the origin, 1 is aligned the farthest away from the origin, 0.5 is centered, etc.
        Specified by:
        getLayoutAlignmentX in interface java.awt.LayoutManager2
        Parameters:
        parent - the parent container
        Returns:
        the value 0.5f to indicate center alignment
      • getLayoutAlignmentY

        public float getLayoutAlignmentY​(java.awt.Container parent)
        Returns the alignment along the y axis. This specifies how the component would like to be aligned relative to other components. The value should be a number between 0 and 1 where 0 represents alignment along the origin, 1 is aligned the farthest away from the origin, 0.5 is centered, etc.
        Specified by:
        getLayoutAlignmentY in interface java.awt.LayoutManager2
        Parameters:
        parent - the parent container
        Returns:
        the value 0.5f to indicate center alignment
      • invalidateLayout

        public void invalidateLayout​(java.awt.Container target)
        Invalidates the layout, indicating that if the layout manager has cached information it should be discarded.
        Specified by:
        invalidateLayout in interface java.awt.LayoutManager2
        Parameters:
        target - the container that holds the layout to be invalidated
      • layoutContainer

        public void layoutContainer​(java.awt.Container parent)
        Lays out the specified container using this form layout. This method reshapes components in the specified container in order to satisfy the constraints of this FormLayout object.

        Most applications do not call this method directly.

        The form layout performs the following steps:

        1. find components that occupy exactly one column or row
        2. compute minimum widths and heights
        3. compute preferred widths and heights
        4. give cols and row equal size if they share a group
        5. compress default columns and rows if total is less than pref size
        6. give cols and row equal size if they share a group
        7. distribute free space
        8. set components bounds
        Specified by:
        layoutContainer in interface java.awt.LayoutManager
        Parameters:
        parent - the container in which to do the layout
        See Also:
        Container, Container.doLayout()
      • initializeColAndRowComponentLists

        private void initializeColAndRowComponentLists()
        Initializes two lists for columns and rows that hold a column's or row's components that span only this column or row.

        Iterates over all components and their associated constraints; every component that has a column span or row span of 1 is put into the column's or row's component list.

      • computeLayoutSize

        private java.awt.Dimension computeLayoutSize​(java.awt.Container parent,
                                                     FormLayout.Measure defaultWidthMeasure,
                                                     FormLayout.Measure defaultHeightMeasure)
        Computes and returns the layout size of the given parent container using the specified measures.
        Parameters:
        parent - the container in which to do the layout
        defaultWidthMeasure - the measure used to compute the default width
        defaultHeightMeasure - the measure used to compute the default height
        Returns:
        the layout size of the parent container
      • computeGridOrigins

        private static int[] computeGridOrigins​(java.awt.Container container,
                                                int totalSize,
                                                int offset,
                                                java.util.List formSpecs,
                                                java.util.List[] componentLists,
                                                int[][] groupIndices,
                                                FormLayout.Measure minMeasure,
                                                FormLayout.Measure prefMeasure)
        Computes and returns the grid's origins.
        Parameters:
        container - the layout container
        totalSize - the total size to assign
        offset - the offset from left or top margin
        formSpecs - the column or row specs, resp.
        componentLists - the components list for each col/row
        minMeasure - the measure used to determine min sizes
        prefMeasure - the measure used to determine pre sizes
        groupIndices - the group specification
        Returns:
        an int array with the origins
      • computeOrigins

        private static int[] computeOrigins​(int[] sizes,
                                            int offset)
        Computes origins from sizes taking the specified offset into account.
        Parameters:
        sizes - the array of sizes
        offset - an offset for the first origin
        Returns:
        an array of origins
      • layoutComponents

        private void layoutComponents​(int[] x,
                                      int[] y)
        Lays out the components using the given x and y origins, the column and row specifications, and the component constraints.

        The actual computation is done by each component's form constraint object. We just compute the cell, the cell bounds and then hand over the component, cell bounds, and measure to the form constraints. This will allow potential subclasses of CellConstraints to do special micro-layout corrections. For example, such a subclass could map JComponent classes to visual layout bounds that may lead to a slightly different bounds.

        Parameters:
        x - an int array of the horizontal origins
        y - an int array of the vertical origins
      • invalidateCaches

        private void invalidateCaches()
        Invalidates the component size caches.
      • maximumSizes

        private static int[] maximumSizes​(java.awt.Container container,
                                          java.util.List formSpecs,
                                          java.util.List[] componentLists,
                                          FormLayout.Measure minMeasure,
                                          FormLayout.Measure prefMeasure,
                                          FormLayout.Measure defaultMeasure)
        Computes and returns the sizes for the given form specs, component lists and measures for minimum, preferred, and default size.
        Parameters:
        container - the layout container
        formSpecs - the column or row specs, resp.
        componentLists - the components list for each col/row
        minMeasure - the measure used to determine min sizes
        prefMeasure - the measure used to determine pre sizes
        defaultMeasure - the measure used to determine default sizes
        Returns:
        the column or row sizes
      • compressedSizes

        private static int[] compressedSizes​(java.util.List formSpecs,
                                             int totalSize,
                                             int totalMinSize,
                                             int totalPrefSize,
                                             int[] minSizes,
                                             int[] prefSizes)
        Computes and returns the compressed sizes. Compresses space for columns and rows iff the available space is less than the total preferred size but more than the total minimum size.

        Only columns and rows that are specified to be compressible will be affected. You can specify a column and row as compressible by giving it the component size default.

        Parameters:
        formSpecs - the column or row specs to use
        totalSize - the total available size
        totalMinSize - the sum of all minimum sizes
        totalPrefSize - the sum of all preferred sizes
        minSizes - an int array of column/row minimum sizes
        prefSizes - an int array of column/row preferred sizes
        Returns:
        an int array of compressed column/row sizes
      • groupedSizes

        private static int[] groupedSizes​(int[][] groups,
                                          int[] rawSizes)
        Computes and returns the grouped sizes. Gives grouped columns and rows the same size.
        Parameters:
        groups - the group specification
        rawSizes - the raw sizes before the grouping
        Returns:
        the grouped sizes
      • distributedSizes

        private static int[] distributedSizes​(java.util.List formSpecs,
                                              int totalSize,
                                              int totalPrefSize,
                                              int[] inputSizes)
        Distributes free space over columns and rows and returns the sizes after this distribution process.
        Parameters:
        formSpecs - the column/row specifications to work with
        totalSize - the total available size
        totalPrefSize - the sum of all preferred sizes
        inputSizes - the input sizes
        Returns:
        the distributed sizes
      • computeMaximumFixedSpanTable

        private static int[] computeMaximumFixedSpanTable​(java.util.List formSpecs)
        Computes and returns a table that maps a column/row index to the maximum number of columns/rows that a component can span without spanning a growing column.

        Iterates over the specs from right to left/bottom to top, sets the table value to zero if a spec can grow, otherwise increases the span by one.

        Examples:

         "pref, 4dlu, pref, 2dlu, p:grow, 2dlu,      pref" ->
         [4,    3,    2,    1,    0,      MAX_VALUE, MAX_VALUE]
        
         "p:grow, 4dlu, p:grow, 9dlu,      pref" ->
         [0,      1,    0,      MAX_VALUE, MAX_VALUE]
        
         "p, 4dlu, p, 2dlu, 0:grow" ->
         [4, 3,    2, 1,    0]
         
        Parameters:
        formSpecs - the column specs or row specs
        Returns:
        a table that maps a spec index to the maximum span for fixed size specs
      • sum

        private static int sum​(int[] sizes)
        Computes and returns the sum of integers in the given array of ints.
        Parameters:
        sizes - an array of ints to sum up
        Returns:
        the sum of ints in the array
      • invalidateAndRepaint

        private static void invalidateAndRepaint​(java.awt.Container container)
      • takeIntoAccount

        private boolean takeIntoAccount​(java.awt.Component component,
                                        CellConstraints cc)
        Checks and answers whether the given component with the specified CellConstraints shall be taken into account for the layout.
        Parameters:
        component - the component to test
        cc - the component's associated CellConstraints
        Returns:
        true if a) component is visible, or b) component has no individual setting and the container-wide settings ignores the visibility, or c) cc indicates that this individual component ignores the visibility.
      • getLayoutInfo

        public FormLayout.LayoutInfo getLayoutInfo​(java.awt.Container parent)
        Computes and returns the horizontal and vertical grid origins. Performs the same layout process as #layoutContainer but does not layout the components.

        This method has been added only to make it easier to debug the form layout. You must not call this method directly; It may be removed in a future release or the visibility may be reduced.

        Parameters:
        parent - the Container to inspect
        Returns:
        an object that comprises the grid x and y origins
      • deepClone

        private static int[][] deepClone​(int[][] array)
        Creates and returns a deep copy of the given array. Unlike #clone that performs a shallow copy, this method copies both array levels.
        Parameters:
        array - the array to clone
        Returns:
        a deep copy of the given array
        See Also:
        Object.clone()
      • writeObject

        private void writeObject​(java.io.ObjectOutputStream out)
                          throws java.io.IOException
        In addition to the default serialization mechanism this class invalidates the component size cache. The cache will be populated again after the deserialization. Also, the fields colComponents and rowComponents have been marked as transient to exclude them from the serialization.
        Throws:
        java.io.IOException