Class ExpandableComposite

All Implemented Interfaces:
Direct Known Subclasses:

public class ExpandableComposite extends Canvas
This composite is capable of expanding or collapsing a single client that is its direct child. The composite renders an expansion toggle affordance (according to the chosen style), and a title that also acts as a hyperlink (can be selected and is traversable). The client is laid out below the title when expanded, or hidden when collapsed.

The widget can be instantiated as-is, or subclassed to modify some aspects of it. *

Since 3.1, left/right arrow keys can be used to control the expansion state. If several expandable composites are created in the same parent, up/down arrow keys can be used to traverse between them. Expandable text accepts mnemonics and mnemonic activation will toggle the expansion state.

While expandable composite recognize that different styles can be used to render the title bar, and even defines the constants for these styles (TITLE_BAR and SHORT_TITLE_BAR the actual painting is done in the subclasses.

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  • Field Details


      public static final int TWISTIE
      If this style is used, a twistie will be used to render the expansion toggle.
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      public static final int TREE_NODE
      If this style is used, a tree node with either + or - signs will be used to render the expansion toggle.
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      public static final int FOCUS_TITLE
      If this style is used, the title text will be rendered as a hyperlink that can individually accept focus. Otherwise, it will still act like a hyperlink, but only the toggle control will accept focus.
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      public static final int CLIENT_INDENT
      If this style is used, the client origin will be vertically aligned with the title text. Otherwise, it will start at x = 0.
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      public static final int COMPACT
      If this style is used, computed size of the composite will take the client width into consideration only in the expanded state. Otherwise, client width will always be taken into account.
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      public static final int EXPANDED
      If this style is used, the control will be created in the expanded state. This state can later be changed programmatically or by the user if TWISTIE or TREE_NODE style is used.
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      public static final int TITLE_BAR
      If this style is used, title bar decoration will be painted behind the text.
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      public static final int SHORT_TITLE_BAR
      If this style is used, a short version of the title bar decoration will be painted behind the text. This style is useful when a more discrete option is needed for the title bar.
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    • NO_TITLE

      public static final int NO_TITLE
      If this style is used, title will not be rendered.
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      public static final int LEFT_TEXT_CLIENT_ALIGNMENT
      By default, text client is right-aligned. If this style is used, it will be positioned after the text control and vertically centered with it.
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      public static final int NO_TITLE_FOCUS_BOX
      By default, a focus box is painted around the title when it receives focus. If this style is used, the focus box will not be painted. This style does not apply when FOCUS_TITLE is used.
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    • marginWidth

      public int marginWidth
      Width of the margin that will be added around the control (default is 0).
    • marginHeight

      public int marginHeight
      Height of the margin that will be added around the control (default is 0).
    • clientVerticalSpacing

      public int clientVerticalSpacing
      Vertical spacing between the title area and the composite client control (default is 3).
    • descriptionVerticalSpacing

      public int descriptionVerticalSpacing
      Vertical spacing between the title area and the description control (default is 0). The description control is normally placed at the new line as defined in the font used to render it. This value will be added to it.
    • titleBarTextMarginWidth

      public int titleBarTextMarginWidth
      Horizontal margin around the inside of the title bar area when TITLE_BAR or SHORT_TITLE_BAR style is used. This variable is not used otherwise.
    • toggle

      protected ToggleHyperlink toggle
      The toggle widget used to expand the composite.
    • textLabel

      protected Control textLabel
      The text label for the title.
    • VGAP

      @Deprecated protected int VGAP
      this variable was left as protected by mistake. It will be turned into static and hidden in the future versions. Do not use them and do not change its value.
    • GAP

      @Deprecated protected int GAP
      this variable was left as protected by mistake. It will be turned into static and hidden in the future versions. Do not use it and do not change its value.
  • Constructor Details

    • ExpandableComposite

      public ExpandableComposite(Composite parent, int style)
      Creates an expandable composite using a TWISTIE toggle.
      parent - the parent composite
      style - SWT style bits
    • ExpandableComposite

      public ExpandableComposite(Composite parent, int style, int expansionStyle)
      Creates the expandable composite in the provided parent.
      parent - the parent
      style - the control style (as expected by SWT subclass)
      expansionStyle - the style of the expansion widget (TREE_NODE, TWISTIE, CLIENT_INDENT, COMPACT, FOCUS_TITLE, LEFT_TEXT_CLIENT_ALIGNMENT, NO_TITLE)
  • Method Details

    • forceFocus

      public boolean forceFocus()
      Description copied from class: Control
      Forces the receiver to have the keyboard focus, causing all keyboard events to be delivered to it.
      forceFocus in class Control
      true if the control got focus, and false if it was unable to.
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    • setMenu

      public void setMenu(Menu menu)
      Overrides 'super' to pass the menu to the text label.
      setMenu in class Control
      menu - the menu from the parent to attach to this control.
    • setLayout

      public final void setLayout(Layout layout)
      Prevents assignment of the layout manager - expandable composite uses its own layout.
      setLayout in class Composite
      layout - the receiver's new layout or null
    • setBackground

      public void setBackground(Color bg)
      Sets the background of all the custom controls in the expandable.
      setBackground in class Control
      bg - the new color (or null)
    • setForeground

      public void setForeground(Color fg)
      Sets the foreground of all the custom controls in the expandable.
      setForeground in class Control
      fg - the new color (or null)
    • setToggleColor

      public void setToggleColor(Color c)
      Sets the color of the toggle control.
      c - the color object
    • setActiveToggleColor

      public void setActiveToggleColor(Color c)
      Sets the active color of the toggle control (when the mouse enters the toggle area).
      c - the active color object
    • setFont

      public void setFont(Font font)
      Sets the fonts of all the custom controls in the expandable.
      setFont in class Canvas
      font - the new font (or null)
    • setEnabled

      public void setEnabled(boolean enabled)
      Description copied from class: Control
      Enables the receiver if the argument is true, and disables it otherwise. A disabled control is typically not selectable from the user interface and draws with an inactive or "grayed" look.
      setEnabled in class Control
      enabled - the new enabled state
    • setClient

      public void setClient(Control client)
      Sets the client of this expandable composite. The client must not be null and must be a direct child of this container.
      client - the client that will be expanded or collapsed
    • getClient

      public Control getClient()
      Returns the current expandable client.
      the client control
    • setText

      public void setText(String title)
      Sets the title of the expandable composite. The title will act as a hyperlink and activating it will toggle the client between expanded and collapsed state.
      title - the new title string
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    • setToolTipText

      public void setToolTipText(String string)
      Description copied from class: Control
      Sets the receiver's tool tip text to the argument, which may be null indicating that the default tool tip for the control will be shown. For a control that has a default tool tip, such as the Tree control on Windows, setting the tool tip text to an empty string replaces the default, causing no tool tip text to be shown.

      The mnemonic indicator (character '&') is not displayed in a tool tip. To display a single '&' in the tool tip, the character '&' can be escaped by doubling it in the string.

      NOTE: This operation is a hint and behavior is platform specific, on Windows for CJK-style mnemonics of the form " (&C)" at the end of the tooltip text are not shown in tooltip.

      setToolTipText in class Control
      string - the new tool tip text (or null)
    • getText

      public String getText()
      Returns the title string.
      the title string
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    • isExpanded

      public boolean isExpanded()
      Tests the expanded state of the composite.
      true if expanded, false if collapsed.
    • getExpansionStyle

      public int getExpansionStyle()
      Returns the bitwise-ORed style bits for the expansion control.
      the bitwise-ORed style bits for the expansion control
    • setExpanded

      public void setExpanded(boolean expanded)
      Programmatically changes expanded state.
      expanded - the new expanded state
    • internalSetExpanded

      protected void internalSetExpanded(boolean expanded)
      Performs the expansion state change for the expandable control.
      expanded - the expansion state
    • addExpansionListener

      public void addExpansionListener(IExpansionListener listener)
      Adds the listener that will be notified when the expansion state changes.
      listener - the listener to add
    • removeExpansionListener

      public void removeExpansionListener(IExpansionListener listener)
      Removes the expansion listener.
      listener - the listener to remove
    • onPaint

      protected void onPaint(PaintEvent e)
      If TITLE_BAR or SHORT_TITLE_BAR style is used, title bar decoration will be painted behind the text in this method. The default implementation does nothing - subclasses are responsible for rendering the title area.
      e - the paint event
    • getDescriptionControl

      protected Control getDescriptionControl()
      Returns description control that will be placed under the title if present.
      the description control or null if not used.
    • getSeparatorControl

      protected Control getSeparatorControl()
      Returns the separator control that will be placed between the title and the description if present.
      the separator control or null if not used.
    • computeSize

      public Point computeSize(int wHint, int hHint, boolean changed)
      Computes the size of the expandable composite.
      computeSize in class Control
      wHint - the width hint (can be SWT.DEFAULT)
      hHint - the height hint (can be SWT.DEFAULT)
      changed - true if the control's contents have changed, and false otherwise
      the preferred size of the control.
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    • isFixedStyle

      protected boolean isFixedStyle()
      Returns true if the composite is fixed i.e. cannot be expanded or collapsed. Fixed control will still contain the title, separator and description (if present) as well as the client, but will be in the permanent expanded state and the toggle affordance will not be shown.
      true if the control is fixed in the expanded state, false if it can be collapsed.
    • getTextClient

      public Control getTextClient()
      Returns the text client control.
      Returns the text client control if specified, or null if not.
    • setTextClient

      public void setTextClient(Control textClient)
      Sets the text client control. Text client is a control that is a child of the expandable composite and is placed to the right of the text. It can be used to place small image hyperlinks. If more than one control is needed, use Composite to hold them. Care should be taken that the height of the control is comparable to the height of the text.
      textClient - the textClient to set or null if not needed any more.
    • getTextClientHeightDifference

      public int getTextClientHeightDifference()
      Returns the difference in height between the text and the text client (if set). This difference can cause vertical alignment problems when two expandable composites are placed side by side, one with and one without the text client. Use this method obtain the value to add to either descriptionVerticalSpacing (if you have description) or clientVerticalSpacing to correct the alignment of the expandable without the text client.
      the difference in height between the text and the text client or 0 if no corrective action is needed.
    • hasTitleBar

      protected boolean hasTitleBar()
      Tests if this expandable composite renders a title bar around the text.
      true for TITLE_BAR or SHORT_TITLE_BAR styles, false otherwise.
    • setTitleBarForeground

      public void setTitleBarForeground(Color color)
      Sets the color of the title bar foreground when TITLE_BAR style is used.
      color - the title bar foreground
    • getTitleBarForeground

      public Color getTitleBarForeground()
      Returns the title bar foreground when TITLE_BAR style is used.
      the title bar foreground