/*******************************************************************************
* Copyright (c) 2006, 2011 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.jface.fieldassist;
import org.eclipse.core.runtime.ListenerList;
import org.eclipse.jface.util.Util;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.DisposeEvent;
import org.eclipse.swt.events.DisposeListener;
import org.eclipse.swt.events.FocusEvent;
import org.eclipse.swt.events.FocusListener;
import org.eclipse.swt.events.MenuDetectEvent;
import org.eclipse.swt.events.MenuDetectListener;
import org.eclipse.swt.events.MouseAdapter;
import org.eclipse.swt.events.MouseEvent;
import org.eclipse.swt.events.MouseMoveListener;
import org.eclipse.swt.events.MouseTrackListener;
import org.eclipse.swt.events.PaintEvent;
import org.eclipse.swt.events.PaintListener;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.graphics.Region;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Widget;
/**
* ControlDecoration renders an image decoration near a control. It allows
* clients to specify an image and a position for the image relative to the
* control. A ControlDecoration may be assigned description text, which can
* optionally be shown when the user hovers over the image. Clients can decorate
* any kind of control.
* <p>
* Decoration images always appear on the left or right side of the field, never
* above or below it. Decorations can be positioned at the top, center, or
* bottom of either side of the control. Future implementations may provide
* additional positioning options for decorations.
* <p>
* ControlDecoration renders the image adjacent to the specified (already
* created) control, with no guarantee that it won't be clipped or otherwise
* obscured or overlapped by adjacent controls, including another
* ControlDecoration placed in the same location. Clients should ensure that
* there is adequate space adjacent to the control to show the decoration
* properly.
* <p>
* Clients using ControlDecoration should typically ensure that enough margin
* space is reserved for a decoration by altering the layout data margins,
* although this is not assumed or required by the ControlDecoration
* implementation.
* <p>
* This class is intended to be instantiated and used by clients. It is not
* intended to be subclassed by clients.
*
* @since 3.3
*
* @see FieldDecoration
* @see FieldDecorationRegistry
*
* @noextend This class is not intended to be subclassed by clients.
*/
public class ControlDecoration {
/**
* Debug flag for tracing
*/
private static boolean DEBUG = false;
/**
* Cached platform flag for dealing with platform-specific issue:
* https://bugs.eclipse.org/bugs/show_bug.cgi?id=219326 : Shell with custom region and SWT.NO_TRIM still has border
*/
private static boolean MAC = Util.isMac();
/**
* The associated control
*/
private Control control;
/**
* The composite on which to render the decoration and hook mouse events, or
* null if we are hooking all parent composites.
*/
private Composite composite;
/**
* The associated image.
*/
private Image image;
/**
* The associated description text.
*/
private String descriptionText;
/**
* The position of the decoration.
*/
private int position;
/**
* The decoration's visibility flag
*/
private boolean visible = true;
/**
* Boolean indicating whether the decoration should only be shown when the
* control has focus
*/
private boolean showOnlyOnFocus = false;
/**
* Boolean indicating whether the decoration should show its description
* text in a hover when the user hovers over the decoration.
*/
private boolean showHover = true;
/**
* Margin width used between the decorator and the control.
*/
private int marginWidth = 0;
/**
* Registered selection listeners.
*/
private ListenerList selectionListeners = new ListenerList();
/**
* Registered menu detect listeners.
*/
private ListenerList menuDetectListeners = new ListenerList();
/**
* The focus listener
*/
private FocusListener focusListener;
/**
* The dispose listener
*/
private DisposeListener disposeListener;
/**
* The paint listener installed for drawing the decoration
*/
private PaintListener paintListener;
/**
* The mouse listener installed for tracking the hover
*/
private MouseTrackListener mouseTrackListener;
/**
* The mouse move listener installed for tracking the hover
*/
private MouseMoveListener mouseMoveListener;
/**
* The untyped listener installed for notifying external listeners
*/
private Listener compositeListener;
/**
* Control that we last installed a move listener on. We only want one at a
* time.
*/
private Control moveListeningTarget = null;
/**
* Debug counter used to match add and remove listeners
*/
private int listenerInstalls = 0;
/**
* The current rectangle used for tracking mouse moves
*/
private Rectangle decorationRectangle;
/**
* The rectangle of the previously used image. Used
* for redrawing in the case where a smaller image replaces
* a larger one.
*
* @since 3.5
*/
private Rectangle previousDecorationRectangle;
/**
* An internal flag tracking whether we have focus. We use this rather than
* isFocusControl() so that we can set the flag as soon as we get the focus
* callback, rather than having to do an asyncExec in the middle of a focus
* callback to ensure that isFocusControl() represents the outcome of the
* event.
*/
private boolean hasFocus = false;
/**
* The hover used for showing description text
*/
private Hover hover;
/**
* The hover used to show a decoration image's description.
*/
class Hover {
private static final String EMPTY = ""; //$NON-NLS-1$
/**
* Offset of info hover arrow from the left or right side.
*/
private int hao = 10;
/**
* Width of info hover arrow.
*/
private int haw = 8;
/**
* Height of info hover arrow.
*/
private int hah = 10;
/**
* Margin around info hover text.
*/
private int hm = 2;
/**
* This info hover's shell.
*/
Shell hoverShell;
/**
* The info hover text.
*/
String text = EMPTY;
/**
* The region used to manage the shell shape
*/
Region region;
/**
* Boolean indicating whether the last computed polygon location had an
* arrow on left. (true if left, false if right).
*/
boolean arrowOnLeft = true;
/*
* Create a hover parented by the specified shell.
*/
Hover(Shell parent) {
final Display display = parent.getDisplay();
hoverShell = new Shell(parent, SWT.NO_TRIM | SWT.ON_TOP
| SWT.NO_FOCUS | SWT.TOOL);
hoverShell.setBackground(display
.getSystemColor(SWT.COLOR_INFO_BACKGROUND));
hoverShell.setForeground(display
.getSystemColor(SWT.COLOR_INFO_FOREGROUND));
hoverShell.addPaintListener(new PaintListener() {
public void paintControl(PaintEvent pe) {
pe.gc.drawText(text, hm, hm);
if (!MAC) {
pe.gc.drawPolygon(getPolygon(true));
}
}
});
hoverShell.addMouseListener(new MouseAdapter() {
public void mouseDown(MouseEvent e) {
hideHover();
}
});
}
/*
* Compute a polygon that represents a hover with an arrow pointer. If
* border is true, compute the polygon inset by 1-pixel border. Consult
* the arrowOnLeft flag to determine which side the arrow is on.
*/
int[] getPolygon(boolean border) {
Point e = getExtent();
int b = border ? 1 : 0;
if (arrowOnLeft) {
return new int[] { 0, 0, e.x - b, 0, e.x - b, e.y - b,
hao + haw, e.y - b, hao + haw / 2, e.y + hah - b, hao,
e.y - b, 0, e.y - b, 0, 0 };
}
return new int[] { 0, 0, e.x - b, 0, e.x - b, e.y - b,
e.x - hao - b, e.y - b, e.x - hao - haw / 2, e.y + hah - b,
e.x - hao - haw, e.y - b, 0, e.y - b, 0, 0 };
}
/*
* Dispose the hover, it is no longer needed. Dispose any resources
* allocated by the hover.
*/
void dispose() {
if (!hoverShell.isDisposed()) {
hoverShell.dispose();
}
if (region != null) {
region.dispose();
}
}
/*
* Set the visibility of the hover.
*/
void setVisible(boolean visible) {
if (visible) {
if (!hoverShell.isVisible()) {
hoverShell.setVisible(true);
}
} else {
if (hoverShell.isVisible()) {
hoverShell.setVisible(false);
}
}
}
/*
* Set the text of the hover to the specified text. Recompute the size
* and location of the hover to hover near the decoration rectangle,
* pointing the arrow toward the target control.
*/
void setText(String t, Rectangle decorationRectangle,
Control targetControl) {
if (t == null) {
t = EMPTY;
}
if (!t.equals(text)) {
Point oldSize = getExtent();
text = t;
hoverShell.redraw();
Point newSize = getExtent();
if (!oldSize.equals(newSize)) {
// set a flag that indicates the direction of arrow
arrowOnLeft = decorationRectangle.x <= targetControl
.getLocation().x;
setNewShape();
}
}
Point extent = getExtent();
int y = -extent.y - hah + 1;
int x = arrowOnLeft ? -hao + haw / 2 : -extent.x + hao + haw / 2;
hoverShell.setLocation(control.getParent().toDisplay(
decorationRectangle.x + x, decorationRectangle.y + y));
}
/*
* Return whether or not the hover (shell) is visible.
*/
boolean isVisible() {
return hoverShell.isVisible();
}
/*
* Compute the extent of the hover for the current text.
*/
Point getExtent() {
GC gc = new GC(hoverShell);
Point e = gc.textExtent(text);
gc.dispose();
e.x += hm * 2;
e.y += hm * 2;
return e;
}
/*
* Compute a new shape for the hover shell.
*/
void setNewShape() {
Region oldRegion = region;
region = new Region();
region.add(getPolygon(false));
hoverShell.setRegion(region);
if (oldRegion != null) {
oldRegion.dispose();
}
}
}
/**
* Construct a ControlDecoration for decorating the specified control at the
* specified position relative to the control. Render the decoration on top
* of any Control that happens to appear at the specified location.
* <p>
* SWT constants are used to specify the position of the decoration relative
* to the control. The position should include style bits describing both
* the vertical and horizontal orientation. <code>SWT.LEFT</code> and
* <code>SWT.RIGHT</code> describe the horizontal placement of the
* decoration relative to the control, and the constants
* <code>SWT.TOP</code>, <code>SWT.CENTER</code>, and
* <code>SWT.BOTTOM</code> describe the vertical alignment of the
* decoration relative to the control. Decorations always appear on either
* the left or right side of the control, never above or below it. For
* example, a decoration appearing on the left side of the field, at the
* top, is specified as SWT.LEFT | SWT.TOP. If no position style bits are
* specified, the control decoration will be positioned to the left and
* center of the control (<code>SWT.LEFT | SWT.CENTER</code>).
* </p>
*
* @param control
* the control to be decorated
* @param position
* bit-wise or of position constants (<code>SWT.TOP</code>,
* <code>SWT.BOTTOM</code>, <code>SWT.LEFT</code>,
* <code>SWT.RIGHT</code>, and <code>SWT.CENTER</code>).
*/
public ControlDecoration(Control control, int position) {
this(control, position, null);
}
/**
* Construct a ControlDecoration for decorating the specified control at the
* specified position relative to the control. Render the decoration only on
* the specified Composite or its children. The decoration will be clipped
* if it does not appear within the visible bounds of the composite or its
* child composites.
* <p>
* SWT constants are used to specify the position of the decoration relative
* to the control. The position should include style bits describing both
* the vertical and horizontal orientation. <code>SWT.LEFT</code> and
* <code>SWT.RIGHT</code> describe the horizontal placement of the
* decoration relative to the control, and the constants
* <code>SWT.TOP</code>, <code>SWT.CENTER</code>, and
* <code>SWT.BOTTOM</code> describe the vertical alignment of the
* decoration relative to the control. Decorations always appear on either
* the left or right side of the control, never above or below it. For
* example, a decoration appearing on the left side of the field, at the
* top, is specified as SWT.LEFT | SWT.TOP. If no position style bits are
* specified, the control decoration will be positioned to the left and
* center of the control (<code>SWT.LEFT | SWT.CENTER</code>).
* </p>
*
* @param control
* the control to be decorated
* @param position
* bit-wise or of position constants (<code>SWT.TOP</code>,
* <code>SWT.BOTTOM</code>, <code>SWT.LEFT</code>,
* <code>SWT.RIGHT</code>, and <code>SWT.CENTER</code>).
* @param composite
* The SWT composite within which the decoration should be
* rendered. The decoration will be clipped to this composite,
* but it may be rendered on a child of the composite. The
* decoration will not be visible if the specified composite or
* its child composites are not visible in the space relative to
* the control, where the decoration is to be rendered. If this
* value is <code>null</code>, then the decoration will be
* rendered on whichever composite (or composites) are located in
* the specified position.
*/
public ControlDecoration(Control control, int position, Composite composite) {
this.position = position;
this.control = control;
this.composite = composite;
addControlListeners();
}
/**
* Adds the listener to the collection of listeners who will be notified
* when the platform-specific context menu trigger has occurred, by sending
* it one of the messages defined in the <code>MenuDetectListener</code>
* interface.
* <p>
* The <code>widget</code> field in the SelectionEvent will contain the
* Composite on which the decoration is rendered that received the click.
* The <code>x</code> and <code>y</code> fields will be in coordinates
* relative to the display. The <code>data</code> field will contain the
* decoration that received the event.
* </p>
*
* @param listener
* the listener which should be notified
*
* @see org.eclipse.swt.events.MenuDetectListener
* @see org.eclipse.swt.events.MenuDetectEvent
* @see #removeMenuDetectListener
*/
public void addMenuDetectListener(MenuDetectListener listener) {
menuDetectListeners.add(listener);
}
/**
* Removes the listener from the collection of listeners who will be
* notified when the platform-specific context menu trigger has occurred.
*
* @param listener
* the listener which should no longer be notified. This message
* has no effect if the listener was not previously added to the
* receiver.
*
* @see org.eclipse.swt.events.MenuDetectListener
* @see #addMenuDetectListener
*/
public void removeMenuDetectListener(MenuDetectListener listener) {
menuDetectListeners.remove(listener);
}
/**
* Adds the listener to the collection of listeners who will be notified
* when the decoration is selected, by sending it one of the messages
* defined in the <code>SelectionListener</code> interface.
* <p>
* <code>widgetSelected</code> is called when the decoration is selected
* (by mouse click). <code>widgetDefaultSelected</code> is called when the
* decoration is double-clicked.
* </p>
* <p>
* The <code>widget</code> field in the SelectionEvent will contain the
* Composite on which the decoration is rendered that received the click.
* The <code>x</code> and <code>y</code> fields will be in coordinates
* relative to that widget. The <code>data</code> field will contain the
* decoration that received the event.
* </p>
*
* @param listener
* the listener which should be notified
*
* @see org.eclipse.swt.events.SelectionListener
* @see org.eclipse.swt.events.SelectionEvent
* @see #removeSelectionListener
*/
public void addSelectionListener(SelectionListener listener) {
selectionListeners.add(listener);
}
/**
* Removes the listener from the collection of listeners who will be
* notified when the decoration is selected.
*
* @param listener
* the listener which should no longer be notified. This message
* has no effect if the listener was not previously added to the
* receiver.
*
* @see org.eclipse.swt.events.SelectionListener
* @see #addSelectionListener
*/
public void removeSelectionListener(SelectionListener listener) {
selectionListeners.remove(listener);
}
/**
* Dispose this ControlDecoration. Unhook any listeners that have been
* installed on the target control. This method has no effect if the
* receiver is already disposed.
*/
public void dispose() {
if (control == null) {
return;
}
if (hover != null) {
hover.dispose();
hover = null;
}
removeControlListeners();
control = null;
}
/**
* Get the control that is decorated by the receiver.
*
* @return the Control decorated by the receiver. May be <code>null</code>
* if the control has been uninstalled.
*/
public Control getControl() {
return control;
}
/**
* Add any listeners needed on the target control and on the composite where
* the decoration is to be rendered.
*/
private void addControlListeners() {
disposeListener = new DisposeListener() {
public void widgetDisposed(DisposeEvent event) {
dispose();
}
};
printAddListener(control, "DISPOSE"); //$NON-NLS-1$
control.addDisposeListener(disposeListener);
focusListener = new FocusListener() {
public void focusGained(FocusEvent event) {
hasFocus = true;
if (showOnlyOnFocus) {
update();
}
}
public void focusLost(FocusEvent event) {
hasFocus = false;
if (showOnlyOnFocus) {
update();
}
}
};
printAddListener(control, "FOCUS"); //$NON-NLS-1$
control.addFocusListener(focusListener);
// Listener for painting the decoration
paintListener = new PaintListener() {
public void paintControl(PaintEvent event) {
Control control = (Control) event.widget;
Rectangle rect = getDecorationRectangle(control);
if (shouldShowDecoration()) {
event.gc.drawImage(getImage(), rect.x, rect.y);
}
}
};
// Listener for tracking the end of a hover. Only installed
// after a hover begins.
mouseMoveListener = new MouseMoveListener() {
public void mouseMove(MouseEvent event) {
if (showHover) {
if (!decorationRectangle.contains(event.x, event.y)) {
hideHover();
// No need to listen any longer
printRemoveListener(event.widget, "MOUSEMOVE"); //$NON-NLS-1$
((Control) event.widget)
.removeMouseMoveListener(mouseMoveListener);
moveListeningTarget = null;
}
}
}
};
// Listener for tracking the beginning of a hover. Always installed.
mouseTrackListener = new MouseTrackListener() {
public void mouseExit(MouseEvent event) {
// Just in case we didn't catch it before.
Control target = (Control) event.widget;
if (target == moveListeningTarget) {
printRemoveListener(target, "MOUSEMOVE"); //$NON-NLS-1$
target.removeMouseMoveListener(mouseMoveListener);
moveListeningTarget = null;
}
hideHover();
}
public void mouseHover(MouseEvent event) {
if (showHover) {
decorationRectangle = getDecorationRectangle((Control) event.widget);
if (decorationRectangle.contains(event.x, event.y)) {
showHoverText(getDescriptionText());
Control target = (Control) event.widget;
if (moveListeningTarget == null) {
printAddListener(target, "MOUSEMOVE"); //$NON-NLS-1$
target.addMouseMoveListener(mouseMoveListener);
moveListeningTarget = target;
} else if (target != moveListeningTarget) {
printRemoveListener(moveListeningTarget,
"MOUSEMOVE"); //$NON-NLS-1$
moveListeningTarget
.removeMouseMoveListener(mouseMoveListener);
printAddListener(target, "MOUSEMOVE"); //$NON-NLS-1$
target.addMouseMoveListener(mouseMoveListener);
moveListeningTarget = target;
} else {
// It is already installed on this control.
}
}
}
}
public void mouseEnter(MouseEvent event) {
// Nothing to do until a hover occurs.
}
};
compositeListener = new Listener() {
public void handleEvent(Event event) {
// Don't forward events if decoration is not showing
if (!visible) {
return;
}
// Notify listeners if any are registered.
switch (event.type) {
case SWT.MouseDown:
if (!selectionListeners.isEmpty())
notifySelectionListeners(event);
break;
case SWT.MouseDoubleClick:
if (!selectionListeners.isEmpty())
notifySelectionListeners(event);
break;
case SWT.MenuDetect:
if (!menuDetectListeners.isEmpty())
notifyMenuDetectListeners(event);
break;
}
}
};
// We do not know which parent in the control hierarchy
// is providing the decoration space, so hook all the way up, until
// the shell or the specified parent composite is reached.
Composite c = control.getParent();
while (c != null) {
installCompositeListeners(c);
if (composite != null && composite == c) {
// We just installed on the specified composite, so stop.
c = null;
} else if (c instanceof Shell) {
// We just installed on a shell, so don't go further
c = null;
} else {
c = c.getParent();
}
}
// force a redraw of the decoration area so our paint listener
// is notified.
update();
}
/*
* Install the listeners used to paint and track mouse events on the
* composite.
*/
private void installCompositeListeners(Composite c) {
if (!c.isDisposed()) {
printAddListener(c, "PAINT"); //$NON-NLS-1$
c.addPaintListener(paintListener);
printAddListener(c, "MOUSETRACK"); //$NON-NLS-1$
c.addMouseTrackListener(mouseTrackListener);
printAddListener(c, "SWT.MenuDetect"); //$NON-NLS-1$
c.addListener(SWT.MenuDetect, compositeListener);
printAddListener(c, "SWT.MouseDown"); //$NON-NLS-1$
c.addListener(SWT.MouseDown, compositeListener);
printAddListener(c, "SWT.MouseDoubleClick"); //$NON-NLS-1$
c.addListener(SWT.MouseDoubleClick, compositeListener);
}
}
/*
* Remove the listeners used to paint and track mouse events on the
* composite.
*/
private void removeCompositeListeners(Composite c) {
if (!c.isDisposed()) {
printRemoveListener(c, "PAINT"); //$NON-NLS-1$
c.removePaintListener(paintListener);
printRemoveListener(c, "MOUSETRACK"); //$NON-NLS-1$
c.removeMouseTrackListener(mouseTrackListener);
printRemoveListener(c, "SWT.MenuDetect"); //$NON-NLS-1$
c.removeListener(SWT.MenuDetect, compositeListener);
printRemoveListener(c, "SWT.MouseDown"); //$NON-NLS-1$
c.removeListener(SWT.MouseDown, compositeListener);
printRemoveListener(c, "SWT.MouseDoubleClick"); //$NON-NLS-1$
c.removeListener(SWT.MouseDoubleClick, compositeListener);
}
}
private void notifySelectionListeners(Event event) {
if (!(event.widget instanceof Control)) {
return;
}
if (getDecorationRectangle((Control) event.widget).contains(event.x,
event.y)) {
SelectionEvent clientEvent = new SelectionEvent(event);
clientEvent.data = this;
if (getImage() != null) {
clientEvent.height = getImage().getBounds().height;
clientEvent.width = getImage().getBounds().width;
}
Object[] listeners;
switch (event.type) {
case SWT.MouseDoubleClick:
if (event.button == 1) {
listeners = selectionListeners.getListeners();
for (int i = 0; i < listeners.length; i++) {
((SelectionListener) listeners[i])
.widgetDefaultSelected(clientEvent);
}
}
break;
case SWT.MouseDown:
if (event.button == 1) {
listeners = selectionListeners.getListeners();
for (int i = 0; i < listeners.length; i++) {
((SelectionListener) listeners[i])
.widgetSelected(clientEvent);
}
}
break;
}
}
}
private void notifyMenuDetectListeners(Event event) {
if (getDecorationRectangle(null).contains(event.x, event.y)) {
MenuDetectEvent clientEvent = new MenuDetectEvent(event);
clientEvent.data = this;
Object[] listeners = menuDetectListeners.getListeners();
for (int i = 0; i < listeners.length; i++) {
((MenuDetectListener) listeners[i]).menuDetected(clientEvent);
}
}
}
/**
* Show the specified text using the same hover dialog as is used to show
* decorator descriptions. When {@link #setShowHover(boolean)} has been set
* to <code>true</code>, a decoration's description text will be shown in
* an info hover over the field's control whenever the mouse hovers over the
* decoration. This method can be used to show a decoration's description
* text at other times (such as when the control receives focus), or to show
* other text associated with the field. The hover will not be shown if the
* decoration is hidden.
*
* @param text
* the text to be shown in the info hover, or <code>null</code>
* if no text should be shown.
*/
public void showHoverText(String text) {
if (control == null) {
return;
}
showHoverText(text, control);
}
/**
* Hide any hover popups that are currently showing on the control. When
* {@link #setShowHover(boolean)} has been set to <code>true</code>, a
* decoration's description text will be shown in an info hover over the
* field's control as long as the mouse hovers over the decoration, and will
* be hidden when the mouse exits the decoration. This method can be used to
* hide a hover, whether it was shown explicitly using
* {@link #showHoverText(String)}, or was showing because the user was
* hovering in the decoration.
* <p>
* This message has no effect if there is no current hover.
*
*/
public void hideHover() {
if (hover != null) {
hover.setVisible(false);
}
}
/**
* Show the control decoration. This message has no effect if the decoration
* is already showing. If {@link #setShowOnlyOnFocus(boolean)} is set to
* <code>true</code>, the decoration will only be shown if the control
* has focus.
*/
public void show() {
if (!visible) {
visible = true;
update();
}
}
/**
* Hide the control decoration and any associated hovers. This message has
* no effect if the decoration is already hidden.
*/
public void hide() {
if (visible) {
visible = false;
hideHover();
update();
}
}
/**
* Get the description text that may be shown in a hover for this
* decoration.
*
* @return the text to be shown as a description for the decoration, or
* <code>null</code> if none has been set.
*/
public String getDescriptionText() {
return descriptionText;
}
/**
* Set the description text that may be shown in a hover for this
* decoration. Update the rendered decoration.
*
* @param text
* the text to be shown as a description for the decoration, or
* <code>null</code> if none has been set.
*/
public void setDescriptionText(String text) {
this.descriptionText = text;
update();
}
/**
* Get the image shown in this control decoration.
*
* @return the image to be shown adjacent to the control, or
* <code>null</code> if one has not been set.
*/
public Image getImage() {
return image;
}
/**
* Set the image shown in this control decoration. Update the rendered
* decoration.
*
* @param image
* the image to be shown adjacent to the control. Should never be
* <code>null</code>.
*/
public void setImage(Image image) {
previousDecorationRectangle = getDecorationRectangle(control.getShell());
this.image = image;
update();
}
/**
* Get the boolean that controls whether the decoration is shown only when
* the control has focus. The default value of this setting is
* <code>false</code>.
*
* @return <code>true</code> if the decoration should only be shown when
* the control has focus, and <code>false</code> if it should
* always be shown. Note that if the control is not capable of
* receiving focus (<code>SWT.NO_FOCUS</code>), then the
* decoration will never show when this value is <code>true</code>.
*/
public boolean getShowOnlyOnFocus() {
return showOnlyOnFocus;
}
/**
* Set the boolean that controls whether the decoration is shown only when
* the control has focus. The default value of this setting is
* <code>false</code>.
*
* @param showOnlyOnFocus
* <code>true</code> if the decoration should only be shown
* when the control has focus, and <code>false</code> if it
* should always be shown. Note that if the control is not
* capable of receiving focus (<code>SWT.NO_FOCUS</code>),
* then the decoration will never show when this value is
* <code>true</code>.
*/
public void setShowOnlyOnFocus(boolean showOnlyOnFocus) {
this.showOnlyOnFocus = showOnlyOnFocus;
update();
}
/**
* Get the boolean that controls whether the decoration's description text
* should be shown in a hover when the user hovers over the decoration. The
* default value of this setting is <code>true</code>.
*
* @return <code>true</code> if a hover popup containing the decoration's
* description text should be shown when the user hovers over the
* decoration, and <code>false</code> if a hover should not be
* shown.
*/
public boolean getShowHover() {
return showHover;
}
/**
* Set the boolean that controls whether the decoration's description text
* should be shown in a hover when the user hovers over the decoration. The
* default value of this setting is <code>true</code>.
*
* @param showHover
* <code>true</code> if a hover popup containing the
* decoration's description text should be shown when the user
* hovers over the decoration, and <code>false</code> if a
* hover should not be shown.
*/
public void setShowHover(boolean showHover) {
this.showHover = showHover;
update();
}
/**
* Get the margin width in pixels that should be used between the decorator
* and the horizontal edge of the control. The default value of this setting
* is <code>0</code>.
*
* @return the number of pixels that should be reserved between the
* horizontal edge of the control and the adjacent edge of the
* decoration.
*/
public int getMarginWidth() {
return marginWidth;
}
/**
* Set the margin width in pixels that should be used between the decorator
* and the horizontal edge of the control. The default value of this setting
* is <code>0</code>.
*
* @param marginWidth
* the number of pixels that should be reserved between the
* horizontal edge of the control and the adjacent edge of the
* decoration.
*/
public void setMarginWidth(int marginWidth) {
previousDecorationRectangle = getDecorationRectangle(control.getShell());
this.marginWidth = marginWidth;
update();
}
/**
* Something has changed, requiring redraw. Redraw the decoration and update
* the hover text if appropriate.
*/
protected void update() {
if (control == null || control.isDisposed()) {
return;
}
Rectangle rect = getDecorationRectangle(control.getShell());
// If this update is happening due to an image reset, we need to make
// sure we clear the area from the old image.
// see https://bugs.eclipse.org/bugs/show_bug.cgi?id=212501
if (previousDecorationRectangle != null) {
rect = rect.union(previousDecorationRectangle);
}
// Redraw this rectangle in all children
control.getShell()
.redraw(rect.x, rect.y, rect.width, rect.height, true);
control.getShell().update();
if (hover != null && getDescriptionText() != null) {
hover.setText(getDescriptionText(), getDecorationRectangle(control
.getParent()), control);
}
previousDecorationRectangle = null;
}
/*
* Show the specified text in the hover, positioning the hover near the
* specified control. The hover will only be shown if the control is
* visible.
*
* The caller has already established that the control is not null.
*/
private void showHoverText(String text, Control hoverNear) {
// We do not show the hover if the control is disposed or
// invisible.
if (control.isDisposed() || !control.isVisible())
return;
// If we aren't to show a hover, don't do anything.
if (!showHover) {
return;
}
// If we are not visible, don't show the hover.
if (!visible) {
return;
}
// If there is no text, any existing hover should be hidden, and
// there is nothing more to do.
if (text == null || text.length() == 0) {
hideHover();
return;
}
// Now we can hover!
// Create the hover if it's not already showing
if (hover == null) {
hover = new Hover(hoverNear.getShell());
}
hover.setText(text, getDecorationRectangle(control.getParent()),
control);
hover.setVisible(true);
}
/*
* Remove any listeners installed on the controls.
*/
private void removeControlListeners() {
if (control == null) {
return;
}
printRemoveListener(control, "FOCUS"); //$NON-NLS-1$
control.removeFocusListener(focusListener);
focusListener = null;
printRemoveListener(control, "DISPOSE"); //$NON-NLS-1$
control.removeDisposeListener(disposeListener);
disposeListener = null;
Composite c = control.getParent();
while (c != null) {
removeCompositeListeners(c);
if (composite != null && composite == c) {
// We previously installed listeners only to the specified
// composite, so stop.
c = null;
} else if (c instanceof Shell) {
// We previously installed listeners only up to the first Shell
// encountered, so stop.
c = null;
} else {
c = c.getParent();
}
}
paintListener = null;
mouseTrackListener = null;
compositeListener = null;
// We may have a remaining mouse move listener installed
if (moveListeningTarget != null) {
printRemoveListener(moveListeningTarget, "MOUSEMOVE"); //$NON-NLS-1$
moveListeningTarget.removeMouseMoveListener(mouseMoveListener);
moveListeningTarget = null;
mouseMoveListener = null;
}
if (DEBUG) {
if (listenerInstalls > 0) {
System.out.println("LISTENER LEAK>>>CHECK TRACE ABOVE"); //$NON-NLS-1$
} else if (listenerInstalls < 0) {
System.out
.println("REMOVED UNREGISTERED LISTENERS>>>CHECK TRACE ABOVE"); //$NON-NLS-1$
} else {
System.out.println("ALL INSTALLED LISTENERS WERE REMOVED."); //$NON-NLS-1$
}
}
}
/**
* Return the rectangle in which the decoration should be rendered, in
* coordinates relative to the specified control. If the specified control
* is null, return the rectangle in display coordinates.
*
* @param targetControl
* the control whose coordinates should be used
* @return the rectangle in which the decoration should be rendered
*/
protected Rectangle getDecorationRectangle(Control targetControl) {
if (getImage() == null || control == null) {
return new Rectangle(0, 0, 0, 0);
}
// Compute the bounds first relative to the control's parent.
Rectangle imageBounds = getImage().getBounds();
Rectangle controlBounds = control.getBounds();
int x, y;
// Compute x
if ((position & SWT.RIGHT) == SWT.RIGHT) {
x = controlBounds.x + controlBounds.width + marginWidth;
} else {
// default is left
x = controlBounds.x - imageBounds.width - marginWidth;
}
// Compute y
if ((position & SWT.TOP) == SWT.TOP) {
y = controlBounds.y;
} else if ((position & SWT.BOTTOM) == SWT.BOTTOM) {
y = controlBounds.y + control.getBounds().height
- imageBounds.height;
} else {
// default is center
y = controlBounds.y
+ (control.getBounds().height - imageBounds.height) / 2;
}
// Now convert to coordinates relative to the target control.
Point globalPoint = control.getParent().toDisplay(x, y);
Point targetPoint;
if (targetControl == null) {
targetPoint = globalPoint;
} else {
targetPoint = targetControl.toControl(globalPoint);
}
return new Rectangle(targetPoint.x, targetPoint.y, imageBounds.width,
imageBounds.height);
}
/*
* Return true if the decoration should be shown, false if it should not.
*/
private boolean shouldShowDecoration() {
if (!visible) {
return false;
}
if (control == null || control.isDisposed() || getImage() == null) {
return false;
}
if (!control.isVisible()) {
return false;
}
if (showOnlyOnFocus) {
return hasFocus;
}
return true;
}
/*
* If in debug mode, print info about adding the specified listener.
*/
private void printAddListener(Widget widget, String listenerType) {
listenerInstalls++;
if (DEBUG) {
System.out
.println("Added listener>>>" + listenerType + " to>>>" + widget); //$NON-NLS-1$//$NON-NLS-2$
}
}
/*
* If in debug mode, print info about adding the specified listener.
*/
private void printRemoveListener(Widget widget, String listenerType) {
listenerInstalls--;
if (DEBUG) {
System.out
.println("Removed listener>>>" + listenerType + " from>>>" + widget); //$NON-NLS-1$//$NON-NLS-2$
}
}
/**
* Return a boolean indicating whether the decoration is visible. This
* method considers the visibility state of the decoration (
* {@link #hide()} and {@link #show()}), the visibility state of the
* associated control ({@link Control#isVisible()}), and the focus state
* of the control if applicable ({@link #setShowOnlyOnFocus(boolean)}.
* When this method returns <code>true</code>, it means that the decoration
* should be visible. However, this method does not consider the case where
* the decoration should be visible, but is obscured by another window or
* control, or positioned off the screen. In these cases, the decoration
* will still be considered visible.
*
* @return <code>true</code> if the decoration is visible, and
* <code>false</code> if it is not.
*
* @see #setShowOnlyOnFocus(boolean)
* @see #hide()
* @see #show()
*
* @since 3.6
*/
public boolean isVisible() {
return shouldShowDecoration();
}
}