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      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  */
     16 package com.android.messaging.ui;
     17 
     18 import android.graphics.drawable.Drawable;
     19 import 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  */
     33 public 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 }