1 /*
2  * Copyright (C) 2012 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
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.inputmethod.keyboard.internal;
18 
19 import android.graphics.Canvas;
20 import android.view.View;
21 
22 import com.android.inputmethod.keyboard.PointerTracker;
23 
24 /**
25  * Abstract base class for previews that are drawn on DrawingPreviewPlacerView, e.g.,
26  * GestureFloatingTextDrawingPreview, GestureTrailsDrawingPreview, and
27  * SlidingKeyInputDrawingPreview.
28  */
29 public abstract class AbstractDrawingPreview {
30     private View mDrawingView;
31     private boolean mPreviewEnabled;
32     private boolean mHasValidGeometry;
33 
setDrawingView(final DrawingPreviewPlacerView drawingView)34     public void setDrawingView(final DrawingPreviewPlacerView drawingView) {
35         mDrawingView = drawingView;
36         drawingView.addPreview(this);
37     }
38 
invalidateDrawingView()39     protected void invalidateDrawingView() {
40         if (mDrawingView != null) {
41             mDrawingView.invalidate();
42         }
43     }
44 
isPreviewEnabled()45     protected final boolean isPreviewEnabled() {
46         return mPreviewEnabled && mHasValidGeometry;
47     }
48 
setPreviewEnabled(final boolean enabled)49     public final void setPreviewEnabled(final boolean enabled) {
50         mPreviewEnabled = enabled;
51     }
52 
53     /**
54      * Set {@link MainKeyboardView} geometry and position in the {@link SoftInputWindow}.
55      * The class that is overriding this method must call this super implementation.
56      *
57      * @param originCoords the top-left coordinates of the {@link MainKeyboardView} in
58      *        {@link SoftInputWindow} coordinate-system. This is unused but has a point in an
59      *        extended class, such as {@link GestureTrailsDrawingPreview}.
60      * @param width the width of {@link MainKeyboardView}.
61      * @param height the height of {@link MainKeyboardView}.
62      */
setKeyboardViewGeometry(final int[] originCoords, final int width, final int height)63     public void setKeyboardViewGeometry(final int[] originCoords, final int width,
64             final int height) {
65         mHasValidGeometry = (width > 0 && height > 0);
66     }
67 
onDeallocateMemory()68     public abstract void onDeallocateMemory();
69 
70     /**
71      * Draws the preview
72      * @param canvas The canvas where the preview is drawn.
73      */
drawPreview(final Canvas canvas)74     public abstract void drawPreview(final Canvas canvas);
75 
76     /**
77      * Set the position of the preview.
78      * @param tracker The new location of the preview is based on the points in PointerTracker.
79      */
setPreviewPosition(final PointerTracker tracker)80     public abstract void setPreviewPosition(final PointerTracker tracker);
81 }
82