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      1 package com.android.launcher3.dragndrop;
      2 
      3 import android.content.Context;
      4 import android.graphics.Bitmap;
      5 import android.graphics.Canvas;
      6 import android.util.AttributeSet;
      7 import android.view.View;
      8 import android.widget.FrameLayout;
      9 import android.widget.RemoteViews;
     10 
     11 import com.android.launcher3.BaseActivity;
     12 import com.android.launcher3.DeviceProfile;
     13 import com.android.launcher3.LauncherAppWidgetProviderInfo;
     14 import com.android.launcher3.widget.WidgetCell;
     15 
     16 /**
     17  * Extension of {@link WidgetCell} which supports generating previews from {@link RemoteViews}
     18  */
     19 public class LivePreviewWidgetCell extends WidgetCell {
     20 
     21     private RemoteViews mPreview;
     22 
     23     public LivePreviewWidgetCell(Context context) {
     24         this(context, null);
     25     }
     26 
     27     public LivePreviewWidgetCell(Context context, AttributeSet attrs) {
     28         this(context, attrs, 0);
     29     }
     30 
     31     public LivePreviewWidgetCell(Context context, AttributeSet attrs, int defStyle) {
     32         super(context, attrs, defStyle);
     33     }
     34 
     35     public void setPreview(RemoteViews view) {
     36         mPreview = view;
     37     }
     38 
     39     @Override
     40     public void ensurePreview() {
     41         if (mPreview != null && mActiveRequest == null) {
     42             Bitmap preview = generateFromRemoteViews(
     43                     mActivity, mPreview, mItem.widgetInfo, mPresetPreviewSize, new int[1]);
     44             if (preview != null) {
     45                 applyPreview(preview);
     46                 return;
     47             }
     48         }
     49         super.ensurePreview();
     50     }
     51 
     52     /**
     53      * Generates a bitmap by inflating {@param views}.
     54      * @see com.android.launcher3.WidgetPreviewLoader#generateWidgetPreview
     55      *
     56      * TODO: Consider moving this to the background thread.
     57      */
     58     public static Bitmap generateFromRemoteViews(BaseActivity activity, RemoteViews views,
     59             LauncherAppWidgetProviderInfo info, int previewSize, int[] preScaledWidthOut) {
     60 
     61         DeviceProfile dp = activity.getDeviceProfile();
     62         int viewWidth = dp.cellWidthPx * info.spanX;
     63         int viewHeight = dp.cellHeightPx * info.spanY;
     64 
     65         final View v;
     66         try {
     67             v = views.apply(activity, new FrameLayout(activity));
     68             v.measure(MeasureSpec.makeMeasureSpec(viewWidth, MeasureSpec.EXACTLY),
     69                     MeasureSpec.makeMeasureSpec(viewHeight, MeasureSpec.EXACTLY));
     70 
     71             viewWidth = v.getMeasuredWidth();
     72             viewHeight = v.getMeasuredHeight();
     73             v.layout(0, 0, viewWidth, viewHeight);
     74         } catch (Exception e) {
     75             return null;
     76         }
     77 
     78         preScaledWidthOut[0] = viewWidth;
     79         final int bitmapWidth, bitmapHeight;
     80         final float scale;
     81         if (viewWidth > previewSize) {
     82             scale = ((float) previewSize) / viewWidth;
     83             bitmapWidth = previewSize;
     84             bitmapHeight = (int) (viewHeight * scale);
     85         } else {
     86             scale = 1;
     87             bitmapWidth = viewWidth;
     88             bitmapHeight = viewHeight;
     89         }
     90 
     91         Bitmap preview = Bitmap.createBitmap(bitmapWidth, bitmapHeight, Bitmap.Config.ARGB_8888);
     92         Canvas c = new Canvas(preview);
     93         c.scale(scale, scale);
     94         v.draw(c);
     95         c.setBitmap(null);
     96         return preview;
     97     }
     98 }
     99