FormLayout (JGoodies Forms 1.9 API)
Date: 2015-02-02

com.jgoodies.forms.layout

## Class FormLayout

- java.lang.Object
- - com.jgoodies.forms.layout.FormLayout

- All Implemented Interfaces:
    LayoutManager, LayoutManager2, Serializable

      public final class FormLayout
      extends Object
      implements LayoutManager2, 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();

  Version:
    $Revision: 1.30 $
  Author:
    Karsten Lentzsch
  See Also:
    `FormBuilder`, `ListViewBuilder`, `ButtonBarBuilder`, `ColumnSpec`, `RowSpec`, `CellConstraints`, `FormSpecs`, `Size`, `Sizes`, Serialized Form

- - ### Nested Class Summary

    Nested Classes
    Modifier and Type | Class and Description
    --- | ---
    `static class` | `FormLayout.LayoutInfo` Stores column and row origins.
    `static interface` | `FormLayout.Measure` An interface that describes how to measure a `Component`.

  - ### Constructor Summary

    Constructors
    Constructor and 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(String encodedColumnSpecs)` Constructs a FormLayout using the given encoded column specifications.
    `FormLayout(String encodedColumnSpecs, LayoutMap layoutMap)` Constructs a FormLayout using the given encoded column specifications and LayoutMap.
    `FormLayout(String encodedColumnSpecs, String encodedRowSpecs)` Constructs a FormLayout using the given encoded column and row specifications and the default LayoutMap.
    `FormLayout(String encodedColumnSpecs, String encodedRowSpecs, LayoutMap layoutMap)` Constructs a FormLayout using the given encoded column and row specifications and the given LayoutMap.

  - ### Method Summary

    Methods
    Modifier and Type | Method and 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(Component comp, Object constraints)` Adds the specified component to the layout, using the specified `constraints` object.
    `void` | `addLayoutComponent(String name, Component component)` Throws an `UnsupportedOperationException`.
    `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.
    `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(Component component)` Looks up and returns the constraints for the specified component.
    `boolean` | `getHonorsVisibility()` Returns whether invisible components shall be taken into account by this layout.
    `float` | `getLayoutAlignmentX(Container parent)` Returns the alignment along the x axis.
    `float` | `getLayoutAlignmentY(Container parent)` Returns the alignment along the y axis.
    `FormLayout.LayoutInfo` | `getLayoutInfo(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.
    `void` | `insertColumn(int columnIndex, ColumnSpec columnSpec)` Inserts the specified column at the specified position.
    `void` | `insertRow(int rowIndex, RowSpec rowSpec)` Inserts the specified row at the specified position.
    `void` | `invalidateLayout(Container target)` Invalidates the layout, indicating that if the layout manager has cached information it should be discarded.
    `void` | `layoutContainer(Container parent)` Lays out the specified container using this form layout.
    `Dimension` | `maximumLayoutSize(Container target)` Returns the maximum dimensions for this layout given the components in the specified target container.
    `Dimension` | `minimumLayoutSize(Container parent)` Determines the minimum size of the `parent` container using this form layout.
    `Dimension` | `preferredLayoutSize(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.
    `void` | `removeLayoutComponent(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.
    `void` | `setColumnSpec(int columnIndex, ColumnSpec columnSpec)` Sets the ColumnSpec at the specified column index.
    `void` | `setConstraints(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(Component component, 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.
    `void` | `setRowSpec(int rowIndex, RowSpec rowSpec)` Sets the RowSpec at the specified row index.

    - ### 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(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:
        `NullPointerException` - if encodedColumnSpecs is `null`
      See Also:
        `LayoutMap.getRoot()`

    - #### FormLayout

          public FormLayout(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:
        `NullPointerException` - if `encodedColumnSpecs` or `layoutMap` is `null`
      Since:
        1.2
      See Also:
        `LayoutMap.getRoot()`

    - #### FormLayout

          public FormLayout(String encodedColumnSpecs,
                    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:
        `NullPointerException` - if encodedColumnSpecs or encodedRowSpecs is `null`
      See Also:
        `LayoutMap.getRoot()`

    - #### FormLayout

          public FormLayout(String encodedColumnSpecs,
                    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:
        `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:
        `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:
        `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:
        `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:
        `NullPointerException` - if `columnSpec` is `null`
        `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:
        `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:
        `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:
        `IndexOutOfBoundsException` - if the column index is out of range
        `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:
        `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:
        `NullPointerException` - if `rowSpec` is `null`
        `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:
        `NullPointerException` - if `rowSpec` is `null`

    - #### insertRow

          public void insertRow(int rowIndex,
                       RowSpec rowSpec)

      Inserts the specified row at the specified position. Shifts components that intersect the new row to the bottom and readjusts row groups.

      The component shift works as follows: components that were located below the inserted row are shifted one row to the bottom; component row span is increased by one if it intersects the new row.

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

      Parameters:
        `rowIndex` - index of the row to be inserted
        `rowSpec` - specification of the row to be inserted
      Throws:
        `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:
        `IndexOutOfBoundsException` - if the row index is out of range
        `IllegalStateException` - if the row contains components or if the row is already grouped
      See Also:
        `FormLayoutUtils.rowContainsComponent(Container, int)`, `FormLayoutUtils.isGroupedRow(FormLayout, int)`

    - #### getConstraints

          public CellConstraints getConstraints(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:
        `NullPointerException` - if `component` is `null`
        `IllegalStateException` - if `component` has not been added to the container

    - #### setConstraints

          public void setConstraints(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:
        `NullPointerException` - if `component` or `constraints` is `null`

    - #### 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:
        `IndexOutOfBoundsException` - if an index is outside the grid
        `IllegalArgumentException` - if a column index is used twice, or of a group of indices contains only a single element

    - #### 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:
        `IndexOutOfBoundsException` - if an index is outside the grid
        `IllegalArgumentException` - if a column index is used twice or if there is only a single index
        `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:
        `IndexOutOfBoundsException` - if an index is outside the grid
        `IllegalArgumentException` - if a column index is used twice, or of a group of indices contains only a single element

    - #### 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:
        `IndexOutOfBoundsException` - if an index is outside the grid
        `IllegalArgumentException` - if a row index is used twice or if there is only a single index
        `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(Component component,
                                 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(String name,
                                Component component)

      Throws an `UnsupportedOperationException`. Does not add the specified component with the specified name to the layout.
      Specified by:
        `addLayoutComponent` in interface `LayoutManager`
      Parameters:
        `name` - indicates entry's position and anchor
        `component` - component to add
      Throws:
        `UnsupportedOperationException` - always

    - #### addLayoutComponent

          public void addLayoutComponent(Component comp,
                                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 `LayoutManager2`
      Parameters:
        `comp` - the component to be added
        `constraints` - the component's cell constraints
      Throws:
        `NullPointerException` - if `constraints` is `null`
        `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(Component comp)

      Removes the specified component from this layout.

      Most applications do not call this method directly.

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

    - #### minimumLayoutSize

          public Dimension minimumLayoutSize(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 `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 Dimension preferredLayoutSize(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 `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 Dimension maximumLayoutSize(Container target)

      Returns the maximum dimensions for this layout given the components in the specified target container.
      Specified by:
        `maximumLayoutSize` in interface `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(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 `LayoutManager2`
      Parameters:
        `parent` - the parent container
      Returns:
        the value `0.5f` to indicate center alignment

    - #### getLayoutAlignmentY

          public float getLayoutAlignmentY(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 `LayoutManager2`
      Parameters:
        `parent` - the parent container
      Returns:
        the value `0.5f` to indicate center alignment

    - #### invalidateLayout

          public void invalidateLayout(Container target)

      Invalidates the layout, indicating that if the layout manager has cached information it should be discarded.
      Specified by:
        `invalidateLayout` in interface `LayoutManager2`
      Parameters:
        `target` - the container that holds the layout to be invalidated

    - #### layoutContainer

          public void layoutContainer(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 `LayoutManager`
      Parameters:
        `parent` - the container in which to do the layout
      See Also:
        `Container`, `Container.doLayout()`

    - #### getLayoutInfo

          public FormLayout.LayoutInfo getLayoutInfo(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

Copyright © 2002-2015 JGoodies Software GmbH. All Rights Reserved.