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      1 /*
      2  * Copyright (C) 2010 The Android Open Source Project
      3  *
      4  * Licensed under the Eclipse Public License, Version 1.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.eclipse.org/org/documents/epl-v10.php
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.android.ide.eclipse.adt.internal.editors.layout.gle2;
     18 
     19 import static com.android.ide.eclipse.adt.internal.editors.layout.gle2.SwtDrawingStyle.HOVER;
     20 import static com.android.ide.eclipse.adt.internal.editors.layout.gle2.SwtDrawingStyle.HOVER_SELECTION;
     21 
     22 import org.eclipse.swt.graphics.Color;
     23 import org.eclipse.swt.graphics.Device;
     24 import org.eclipse.swt.graphics.GC;
     25 import org.eclipse.swt.graphics.Rectangle;
     26 
     27 import java.util.List;
     28 
     29 /**
     30  * The {@link HoverOverlay} paints an optional hover on top of the layout,
     31  * highlighting the currently hovered view.
     32  */
     33 public class HoverOverlay extends Overlay {
     34     private final LayoutCanvas mCanvas;
     35 
     36     /** Hover border color. Must be disposed, it's NOT a system color. */
     37     private Color mHoverStrokeColor;
     38 
     39     /** Hover fill color. Must be disposed, it's NOT a system color. */
     40     private Color mHoverFillColor;
     41 
     42     /** Hover border select color. Must be disposed, it's NOT a system color. */
     43     private Color mHoverSelectStrokeColor;
     44 
     45     /** Hover fill select color. Must be disposed, it's NOT a system color. */
     46     private Color mHoverSelectFillColor;
     47 
     48     /** Vertical scaling & scrollbar information. */
     49     private CanvasTransform mVScale;
     50 
     51     /** Horizontal scaling & scrollbar information. */
     52     private CanvasTransform mHScale;
     53 
     54     /**
     55      * Current mouse hover border rectangle. Null when there's no mouse hover.
     56      * The rectangle coordinates do not take account of the translation, which
     57      * must be applied to the rectangle when drawing.
     58      */
     59     private Rectangle mHoverRect;
     60 
     61     /**
     62      * Constructs a new {@link HoverOverlay} linked to the given view hierarchy.
     63      *
     64      * @param canvas the associated canvas
     65      * @param hScale The {@link CanvasTransform} to use to transfer horizontal layout
     66      *            coordinates to screen coordinates.
     67      * @param vScale The {@link CanvasTransform} to use to transfer vertical layout
     68      *            coordinates to screen coordinates.
     69      */
     70     public HoverOverlay(LayoutCanvas canvas, CanvasTransform hScale, CanvasTransform vScale) {
     71         mCanvas = canvas;
     72         mHScale = hScale;
     73         mVScale = vScale;
     74     }
     75 
     76     @Override
     77     public void create(Device device) {
     78         if (SwtDrawingStyle.HOVER.getStrokeColor() != null) {
     79             mHoverStrokeColor = new Color(device, SwtDrawingStyle.HOVER.getStrokeColor());
     80         }
     81         if (SwtDrawingStyle.HOVER.getFillColor() != null) {
     82             mHoverFillColor = new Color(device, SwtDrawingStyle.HOVER.getFillColor());
     83         }
     84 
     85         if (SwtDrawingStyle.HOVER_SELECTION.getStrokeColor() != null) {
     86             mHoverSelectStrokeColor = new Color(device,
     87                     SwtDrawingStyle.HOVER_SELECTION.getStrokeColor());
     88         }
     89         if (SwtDrawingStyle.HOVER_SELECTION.getFillColor() != null) {
     90             mHoverSelectFillColor = new Color(device,
     91                     SwtDrawingStyle.HOVER_SELECTION.getFillColor());
     92         }
     93     }
     94 
     95     @Override
     96     public void dispose() {
     97         if (mHoverStrokeColor != null) {
     98             mHoverStrokeColor.dispose();
     99             mHoverStrokeColor = null;
    100         }
    101 
    102         if (mHoverFillColor != null) {
    103             mHoverFillColor.dispose();
    104             mHoverFillColor = null;
    105         }
    106 
    107         if (mHoverSelectStrokeColor != null) {
    108             mHoverSelectStrokeColor.dispose();
    109             mHoverSelectStrokeColor = null;
    110         }
    111 
    112         if (mHoverSelectFillColor != null) {
    113             mHoverSelectFillColor.dispose();
    114             mHoverSelectFillColor = null;
    115         }
    116     }
    117 
    118     /**
    119      * Sets the hover rectangle. The coordinates of the rectangle are in layout
    120      * coordinates. The recipient is will own this rectangle.
    121      * <p/>
    122      * TODO: Consider switching input arguments to two {@link LayoutPoint}s so
    123      * we don't have ambiguity about the coordinate system of these input
    124      * parameters.
    125      * <p/>
    126      *
    127      * @param x The top left x coordinate, in layout coordinates, of the hover.
    128      * @param y The top left y coordinate, in layout coordinates, of the hover.
    129      * @param w The width of the hover (in layout coordinates).
    130      * @param h The height of the hover (in layout coordinates).
    131      */
    132     public void setHover(int x, int y, int w, int h) {
    133         mHoverRect = new Rectangle(x, y, w, h);
    134     }
    135 
    136     /**
    137      * Removes the hover for the next paint.
    138      */
    139     public void clearHover() {
    140         mHoverRect = null;
    141     }
    142 
    143     @Override
    144     public void paint(GC gc) {
    145         if (mHoverRect != null) {
    146             // Translate the hover rectangle (in canvas coordinates) to control
    147             // coordinates
    148             int x = mHScale.translate(mHoverRect.x);
    149             int y = mVScale.translate(mHoverRect.y);
    150             int w = mHScale.scale(mHoverRect.width);
    151             int h = mVScale.scale(mHoverRect.height);
    152 
    153 
    154             boolean hoverIsSelected = false;
    155             List<SelectionItem> selections = mCanvas.getSelectionManager().getSelections();
    156             for (SelectionItem item : selections) {
    157                 if (mHoverRect.equals(item.getViewInfo().getSelectionRect())) {
    158                     hoverIsSelected = true;
    159                     break;
    160                 }
    161             }
    162 
    163             Color stroke = hoverIsSelected ? mHoverSelectStrokeColor : mHoverStrokeColor;
    164             Color fill = hoverIsSelected ? mHoverSelectFillColor : mHoverFillColor;
    165 
    166             if (stroke != null) {
    167                 int oldAlpha = gc.getAlpha();
    168                 gc.setForeground(stroke);
    169                 gc.setLineStyle(hoverIsSelected ?
    170                         HOVER_SELECTION.getLineStyle() : HOVER.getLineStyle());
    171                 gc.setAlpha(hoverIsSelected ?
    172                         HOVER_SELECTION.getStrokeAlpha() : HOVER.getStrokeAlpha());
    173                 gc.drawRectangle(x, y, w, h);
    174                 gc.setAlpha(oldAlpha);
    175             }
    176 
    177             if (fill != null) {
    178                 int oldAlpha = gc.getAlpha();
    179                 gc.setAlpha(hoverIsSelected ?
    180                         HOVER_SELECTION.getFillAlpha() : HOVER.getFillAlpha());
    181                 gc.setBackground(fill);
    182                 gc.fillRectangle(x, y, w, h);
    183                 gc.setAlpha(oldAlpha);
    184             }
    185         }
    186     }
    187 }
    188