BitmapUtils.java 文件源码

/**
 * Creates a Material Design compliant {@link android.support.v7.widget.Toolbar} icon
 * from a given full sized icon.
 *
 * @param resources Resources for the current {@link android.content.Context}.
 * @param icon The bitmap to convert.
 * @return A scaled Bitmap of the appropriate size and in-built padding.
 */
public static Bitmap createToolbarIcon(@NonNull Resources resources,
                                       @NonNull final Bitmap icon) {
    final int padding = resources.getDimensionPixelSize(R.dimen.margin_small);
    final int iconSize = resources.getDimensionPixelSize(R.dimen.toolbar_icon_size);
    final int sizeWithPadding = iconSize + (2 * padding);

    // Create a Bitmap backed Canvas to be the toolbar icon.
    final Bitmap toolbarIcon =
            Bitmap.createBitmap(sizeWithPadding, sizeWithPadding, Bitmap.Config.ARGB_8888);
    final Canvas canvas = new Canvas(toolbarIcon);
    canvas.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR);

    // Resize the app icon to Material Design size.
    final Bitmap scaledIcon = Bitmap.createScaledBitmap(icon, iconSize, iconSize, false);
    canvas.drawBitmap(scaledIcon, padding, padding, null);

    return toolbarIcon;
}