eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gle2/GestureToolTip.java - platform/sdk - Git at Google

 /*
  * Copyright (C) 2011 The Android Open Source Project
  *
  * Licensed under the Eclipse Public License, Version 1.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.eclipse.org/org/documents/epl-v10.php
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 package com.android.ide.eclipse.adt.internal.editors.layout.gle2;

 import org.eclipse.swt.SWT;
 import org.eclipse.swt.custom.CLabel;
 import org.eclipse.swt.graphics.Font;
 import org.eclipse.swt.graphics.FontData;
 import org.eclipse.swt.graphics.Point;
 import org.eclipse.swt.layout.FillLayout;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.swt.widgets.Display;
 import org.eclipse.swt.widgets.Shell;

 /**
  * A dedicated tooltip used during gestures, for example to show the resize dimensions.
  * <p>
  * This is necessary because {@link org.eclipse.jface.window.ToolTip} causes flicker when
  * used to dynamically update the position and text of the tip, and it does not seem to
  * have setter methods to update the text or position without recreating the tip.
  */
 public class GestureToolTip {
     /** Minimum number of milliseconds to wait between alignment changes */
     private static final int TIMEOUT_MS = 750;

     /**
      * The alpha to use for the tooltip window (which sadly will apply to the tooltip text
      * as well.)
      */
     private static final int SHELL_TRANSPARENCY = 220;

     /** The size of the font displayed in the tooltip */
     private static final int FONT_SIZE = 9;

     /** Horizontal delta from the mouse cursor to shift the tooltip by */
     private static final int OFFSET_X = 20;

     /** Vertical delta from the mouse cursor to shift the tooltip by */
     private static final int OFFSET_Y = 20;

     /** The label which displays the tooltip */
     private CLabel mLabel;

     /** The shell holding the tooltip */
     private Shell mShell;

     /** The font shown in the label; held here such that it can be disposed of after use */
     private Font mFont;

     /** Is the tooltip positioned below the given anchor? */
     private boolean mBelow;

     /** Is the tooltip positioned to the right of the given anchor? */
     private boolean mToRightOf;

     /** Is an alignment change pending? */
     private boolean mTimerPending;

     /** The new value for {@link #mBelow} when the timer expires */
     private boolean mPendingBelow;

     /** The new value for {@link #mToRightOf} when the timer expires */
     private boolean mPendingRight;

     /** The time stamp (from {@link System#currentTimeMillis()} of the last alignment change */
     private long mLastAlignmentTime;

     /**
      * Creates a new tooltip over the given parent with the given relative position.
      *
      * @param parent the parent control
      * @param below if true, display the tooltip below the mouse cursor otherwise above
      * @param toRightOf if true, display the tooltip to the right of the mouse cursor,
      *            otherwise to the left
      */
     public GestureToolTip(Composite parent, boolean below, boolean toRightOf) {
         mBelow = below;
         mToRightOf = toRightOf;
         mLastAlignmentTime = System.currentTimeMillis();

         mShell = new Shell(parent.getShell(), SWT.ON_TOP | SWT.TOOL | SWT.NO_FOCUS);
         mShell.setLayout(new FillLayout());
         mShell.setAlpha(SHELL_TRANSPARENCY);

         Display display = parent.getDisplay();
         mLabel = new CLabel(mShell, SWT.SHADOW_NONE);
         mLabel.setBackground(display.getSystemColor(SWT.COLOR_INFO_BACKGROUND));
         mLabel.setForeground(display.getSystemColor(SWT.COLOR_INFO_FOREGROUND));

         Font systemFont = display.getSystemFont();
         FontData[] fd = systemFont.getFontData();
         for (int i = 0; i < fd.length; i++) {
             fd[i].setHeight(FONT_SIZE);
         }
         mFont = new Font(display, fd);
         mLabel.setFont(mFont);

         mShell.setVisible(false);
     }

     /**
      * Show the tooltip at the given position and with the given text. Note that the
      * position may not be applied immediately; to prevent flicker alignment changes
      * are queued up with a timer (unless it's been a while since the last change, in
      * which case the update is applied immediately.)
      *
      * @param text the new text to be displayed
      * @param below if true, display the tooltip below the mouse cursor otherwise above
      * @param toRightOf if true, display the tooltip to the right of the mouse cursor,
      *            otherwise to the left
      */
     public void update(final String text, boolean below, boolean toRightOf) {
         // If the alignment has not changed recently, just apply the change immediately
         // instead of within a delay
         if (!mTimerPending && (below != mBelow || toRightOf != mToRightOf)
                 && (System.currentTimeMillis() - mLastAlignmentTime >= TIMEOUT_MS)) {
             mBelow = below;
             mToRightOf = toRightOf;
             mLastAlignmentTime = System.currentTimeMillis();
         }

         Point location = mShell.getDisplay().getCursorLocation();

         mLabel.setText(text);

         // Pack the label to its minimum size -- unless we are positioning the tooltip
         // on the left. Because of the way SWT works (at least on the OSX) this sometimes
         // creates flicker, because when we switch to a longer string (such as when
         // switching from "52dp" to "wrap_content" during a resize) the window size will
         // change first, and then the location will update later - so there will be a
         // brief flash of the longer label before it is moved to the right position on the
         // left. To work around this, we simply pass false to pack such that it will reuse
         // its cached size, which in practice means that for labels on the right, the
         // label will grow but not shrink.
         // This workaround is disabled because it doesn't work well in Eclipse 3.5; the
         // labels don't grow when they should. Re-enable when we drop 3.5 support.
         //boolean changed = mToRightOf;
         boolean changed = true;

         mShell.pack(changed);
         Point size = mShell.getSize();

         // Position the tooltip to the left or right, and above or below, according
         // to the saved state of these flags, not the current parameters. We don't want
         // to flicker, instead we react on a timer to changes in alignment below.
         if (mBelow) {
             location.y += OFFSET_Y;
         } else {
             location.y -= OFFSET_Y;
             location.y -= size.y;
         }

         if (mToRightOf) {
             location.x += OFFSET_X;
         } else {
             location.x -= OFFSET_X;
             location.x -= size.x;
         }

         mShell.setLocation(location);

         if (!mShell.isVisible()) {
             mShell.setVisible(true);
         }

         // Has the orientation changed?
         mPendingBelow = below;
         mPendingRight = toRightOf;
         if (below != mBelow || toRightOf != mToRightOf) {
             // Yes, so schedule a timer (unless one is already scheduled)
             if (!mTimerPending) {
                 mTimerPending = true;
                 final Runnable timer = new Runnable() {
                     @Override
                     public void run() {
                         mTimerPending = false;
                         // Check whether the alignment is still different than the target
                         // (since we may change back and forth repeatedly during the timeout)
                         if (mBelow != mPendingBelow || mToRightOf != mPendingRight) {
                             mBelow = mPendingBelow;
                             mToRightOf = mPendingRight;
                             mLastAlignmentTime = System.currentTimeMillis();
                             if (mShell != null && mShell.isVisible()) {
                                 update(text, mBelow, mToRightOf);
                             }
                         }
                     }
                 };
                 mShell.getDisplay().timerExec(TIMEOUT_MS, timer);
             }
         }
     }

     /** Hide the tooltip and dispose of any associated resources */
     public void dispose() {
         mShell.dispose();
         mFont.dispose();

         mShell = null;
         mFont = null;
         mLabel = null;
     }
 }
	/*
	* Copyright (C) 2011 The Android Open Source Project
	*
	* Licensed under the Eclipse Public License, Version 1.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.eclipse.org/org/documents/epl-v10.php
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package com.android.ide.eclipse.adt.internal.editors.layout.gle2;

	import org.eclipse.swt.SWT;
	import org.eclipse.swt.custom.CLabel;
	import org.eclipse.swt.graphics.Font;
	import org.eclipse.swt.graphics.FontData;
	import org.eclipse.swt.graphics.Point;
	import org.eclipse.swt.layout.FillLayout;
	import org.eclipse.swt.widgets.Composite;
	import org.eclipse.swt.widgets.Display;
	import org.eclipse.swt.widgets.Shell;

	/**
	* A dedicated tooltip used during gestures, for example to show the resize dimensions.
	* <p>
	* This is necessary because {@link org.eclipse.jface.window.ToolTip} causes flicker when
	* used to dynamically update the position and text of the tip, and it does not seem to
	* have setter methods to update the text or position without recreating the tip.
	*/
	public class GestureToolTip {
	/** Minimum number of milliseconds to wait between alignment changes */
	private static final int TIMEOUT_MS = 750;

	/**
	* The alpha to use for the tooltip window (which sadly will apply to the tooltip text
	* as well.)
	*/
	private static final int SHELL_TRANSPARENCY = 220;

	/** The size of the font displayed in the tooltip */
	private static final int FONT_SIZE = 9;

	/** Horizontal delta from the mouse cursor to shift the tooltip by */
	private static final int OFFSET_X = 20;

	/** Vertical delta from the mouse cursor to shift the tooltip by */
	private static final int OFFSET_Y = 20;

	/** The label which displays the tooltip */
	private CLabel mLabel;

	/** The shell holding the tooltip */
	private Shell mShell;

	/** The font shown in the label; held here such that it can be disposed of after use */
	private Font mFont;

	/** Is the tooltip positioned below the given anchor? */
	private boolean mBelow;

	/** Is the tooltip positioned to the right of the given anchor? */
	private boolean mToRightOf;

	/** Is an alignment change pending? */
	private boolean mTimerPending;

	/** The new value for {@link #mBelow} when the timer expires */
	private boolean mPendingBelow;

	/** The new value for {@link #mToRightOf} when the timer expires */
	private boolean mPendingRight;

	/** The time stamp (from {@link System#currentTimeMillis()} of the last alignment change */
	private long mLastAlignmentTime;

	/**
	* Creates a new tooltip over the given parent with the given relative position.
	*
	* @param parent the parent control
	* @param below if true, display the tooltip below the mouse cursor otherwise above
	* @param toRightOf if true, display the tooltip to the right of the mouse cursor,
	* otherwise to the left
	*/
	public GestureToolTip(Composite parent, boolean below, boolean toRightOf) {
	mBelow = below;
	mToRightOf = toRightOf;
	mLastAlignmentTime = System.currentTimeMillis();

	mShell = new Shell(parent.getShell(), SWT.ON_TOP \| SWT.TOOL \| SWT.NO_FOCUS);
	mShell.setLayout(new FillLayout());
	mShell.setAlpha(SHELL_TRANSPARENCY);

	Display display = parent.getDisplay();
	mLabel = new CLabel(mShell, SWT.SHADOW_NONE);
	mLabel.setBackground(display.getSystemColor(SWT.COLOR_INFO_BACKGROUND));
	mLabel.setForeground(display.getSystemColor(SWT.COLOR_INFO_FOREGROUND));

	Font systemFont = display.getSystemFont();
	FontData[] fd = systemFont.getFontData();
	for (int i = 0; i < fd.length; i++) {
	fd[i].setHeight(FONT_SIZE);
	}
	mFont = new Font(display, fd);
	mLabel.setFont(mFont);

	mShell.setVisible(false);
	}

	/**
	* Show the tooltip at the given position and with the given text. Note that the
	* position may not be applied immediately; to prevent flicker alignment changes
	* are queued up with a timer (unless it's been a while since the last change, in
	* which case the update is applied immediately.)
	*
	* @param text the new text to be displayed
	* @param below if true, display the tooltip below the mouse cursor otherwise above
	* @param toRightOf if true, display the tooltip to the right of the mouse cursor,
	* otherwise to the left
	*/
	public void update(final String text, boolean below, boolean toRightOf) {
	// If the alignment has not changed recently, just apply the change immediately
	// instead of within a delay
	if (!mTimerPending && (below != mBelow \|\| toRightOf != mToRightOf)
	&& (System.currentTimeMillis() - mLastAlignmentTime >= TIMEOUT_MS)) {
	mBelow = below;
	mToRightOf = toRightOf;
	mLastAlignmentTime = System.currentTimeMillis();
	}

	Point location = mShell.getDisplay().getCursorLocation();

	mLabel.setText(text);

	// Pack the label to its minimum size -- unless we are positioning the tooltip
	// on the left. Because of the way SWT works (at least on the OSX) this sometimes
	// creates flicker, because when we switch to a longer string (such as when
	// switching from "52dp" to "wrap_content" during a resize) the window size will
	// change first, and then the location will update later - so there will be a
	// brief flash of the longer label before it is moved to the right position on the
	// left. To work around this, we simply pass false to pack such that it will reuse
	// its cached size, which in practice means that for labels on the right, the
	// label will grow but not shrink.
	// This workaround is disabled because it doesn't work well in Eclipse 3.5; the
	// labels don't grow when they should. Re-enable when we drop 3.5 support.
	//boolean changed = mToRightOf;
	boolean changed = true;

	mShell.pack(changed);
	Point size = mShell.getSize();

	// Position the tooltip to the left or right, and above or below, according
	// to the saved state of these flags, not the current parameters. We don't want
	// to flicker, instead we react on a timer to changes in alignment below.
	if (mBelow) {
	location.y += OFFSET_Y;
	} else {
	location.y -= OFFSET_Y;
	location.y -= size.y;
	}

	if (mToRightOf) {
	location.x += OFFSET_X;
	} else {
	location.x -= OFFSET_X;
	location.x -= size.x;
	}

	mShell.setLocation(location);

	if (!mShell.isVisible()) {
	mShell.setVisible(true);
	}

	// Has the orientation changed?
	mPendingBelow = below;
	mPendingRight = toRightOf;
	if (below != mBelow \|\| toRightOf != mToRightOf) {
	// Yes, so schedule a timer (unless one is already scheduled)
	if (!mTimerPending) {
	mTimerPending = true;
	final Runnable timer = new Runnable() {
	@Override
	public void run() {
	mTimerPending = false;
	// Check whether the alignment is still different than the target
	// (since we may change back and forth repeatedly during the timeout)
	if (mBelow != mPendingBelow \|\| mToRightOf != mPendingRight) {
	mBelow = mPendingBelow;
	mToRightOf = mPendingRight;
	mLastAlignmentTime = System.currentTimeMillis();
	if (mShell != null && mShell.isVisible()) {
	update(text, mBelow, mToRightOf);
	}
	}
	}
	};
	mShell.getDisplay().timerExec(TIMEOUT_MS, timer);
	}
	}
	}

	/** Hide the tooltip and dispose of any associated resources */
	public void dispose() {
	mShell.dispose();
	mFont.dispose();

	mShell = null;
	mFont = null;
	mLabel = null;
	}
	}