1/*
2 * Copyright (C) 2015 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 */
16package com.android.messaging.ui;
17
18import android.graphics.drawable.Drawable;
19import android.graphics.drawable.InsetDrawable;
20
21/**
22 * A "placeholder" drawable that has the same sizing properties as the real UI element it
23 * replaces.
24 *
25 * This is an InsetDrawable that takes a placeholder drawable (an animation list, or simply
26 * a color drawable) and place it in the center of the inset drawable that's sized to the
27 * requested source width and height of the image that it replaces. Unlike the base
28 * InsetDrawable, this implementation returns the true width and height of the real image
29 * that it's placeholding, instead of the intrinsic size of the contained drawable, so that
30 * when used in an ImageView, it may be positioned/scaled/cropped the same way the real
31 * image is.
32 */
33public class PlaceholderInsetDrawable extends InsetDrawable {
34    // The dimensions of the real image that this drawable is replacing.
35    private final int mSourceWidth;
36    private final int mSourceHeight;
37
38    /**
39     * Given a source drawable, wraps it around in this placeholder drawable by placing the
40     * drawable at the center of the container if possible (or fill the container if the
41     * drawable doesn't have intrinsic size such as color drawable).
42     */
43    public static PlaceholderInsetDrawable fromDrawable(final Drawable drawable,
44            final int sourceWidth, final int sourceHeight) {
45        final int drawableWidth = drawable.getIntrinsicWidth();
46        final int drawableHeight = drawable.getIntrinsicHeight();
47        final int insetHorizontal = drawableWidth < 0 || drawableWidth > sourceWidth ?
48                0 : (sourceWidth - drawableWidth) / 2;
49        final int insetVertical = drawableHeight < 0 || drawableHeight > sourceHeight ?
50                0 : (sourceHeight - drawableHeight) / 2;
51        return new PlaceholderInsetDrawable(drawable, insetHorizontal, insetVertical,
52                insetHorizontal, insetVertical, sourceWidth, sourceHeight);
53    }
54
55    private PlaceholderInsetDrawable(final Drawable drawable, final int insetLeft,
56            final int insetTop, final int insetRight, final int insetBottom,
57            final int sourceWidth, final int sourceHeight) {
58        super(drawable, insetLeft, insetTop, insetRight, insetBottom);
59        mSourceWidth = sourceWidth;
60        mSourceHeight = sourceHeight;
61    }
62
63    @Override
64    public int getIntrinsicWidth() {
65        return mSourceWidth;
66    }
67
68    @Override
69    public int getIntrinsicHeight() {
70        return mSourceHeight;
71    }
72}