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.MainKeyboardView;
23 import com.android.inputmethod.keyboard.PointerTracker;
24 
25 import javax.annotation.Nonnull;
26 
27 /**
28  * Abstract base class for previews that are drawn on DrawingPreviewPlacerView, e.g.,
29  * GestureFloatingTextDrawingPreview, GestureTrailsDrawingPreview, and
30  * SlidingKeyInputDrawingPreview.
31  */
32 public abstract class AbstractDrawingPreview {
33     private View mDrawingView;
34     private boolean mPreviewEnabled;
35     private boolean mHasValidGeometry;
36 
setDrawingView(@onnull final DrawingPreviewPlacerView drawingView)37     public void setDrawingView(@Nonnull final DrawingPreviewPlacerView drawingView) {
38         mDrawingView = drawingView;
39         drawingView.addPreview(this);
40     }
41 
invalidateDrawingView()42     protected void invalidateDrawingView() {
43         if (mDrawingView != null) {
44             mDrawingView.invalidate();
45         }
46     }
47 
isPreviewEnabled()48     protected final boolean isPreviewEnabled() {
49         return mPreviewEnabled && mHasValidGeometry;
50     }
51 
setPreviewEnabled(final boolean enabled)52     public final void setPreviewEnabled(final boolean enabled) {
53         mPreviewEnabled = enabled;
54     }
55 
56     /**
57      * Set {@link MainKeyboardView} geometry and position in the window of input method.
58      * The class that is overriding this method must call this super implementation.
59      *
60      * @param originCoords the top-left coordinates of the {@link MainKeyboardView} in
61      *        the input method window coordinate-system. This is unused but has a point in an
62      *        extended class, such as {@link GestureTrailsDrawingPreview}.
63      * @param width the width of {@link MainKeyboardView}.
64      * @param height the height of {@link MainKeyboardView}.
65      */
setKeyboardViewGeometry(@onnull final int[] originCoords, final int width, final int height)66     public void setKeyboardViewGeometry(@Nonnull final int[] originCoords, final int width,
67             final int height) {
68         mHasValidGeometry = (width > 0 && height > 0);
69     }
70 
onDeallocateMemory()71     public abstract void onDeallocateMemory();
72 
73     /**
74      * Draws the preview
75      * @param canvas The canvas where the preview is drawn.
76      */
drawPreview(@onnull final Canvas canvas)77     public abstract void drawPreview(@Nonnull final Canvas canvas);
78 
79     /**
80      * Set the position of the preview.
81      * @param tracker The new location of the preview is based on the points in PointerTracker.
82      */
setPreviewPosition(@onnull final PointerTracker tracker)83     public abstract void setPreviewPosition(@Nonnull final PointerTracker tracker);
84 }
85