创建裁剪视图

Question

我正在尝试实现自己的裁剪屏幕。

见下图：

布局有背景，图像有侦听器在屏幕上移动和缩放。我有'裁剪透明层'和框架的framelayout。

这是我到目前为止所做的：

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >

<!-- This is the transparent border -->
<item
    android:id="@+id/crop_transparent_top"
    android:bottom="550dp">
    <shape android:shape="rectangle" >
        <solid android:color="#AA0A0A0A" />
    </shape>
</item>
<item
    android:id="@+id/crop_transparent_bottom"
    android:top="550dp">
    <shape android:shape="rectangle" >
        <solid android:color="#AA0A0A0A" />
    </shape>
</item>
<item
    android:id="@+id/crop_transparent_right"
    android:bottom="110dp"
    android:left="1000dp"
    android:top="110dp">
    <shape android:shape="rectangle" >
        <solid android:color="#AA0A0A0A" />
    </shape>
</item>
<item
    android:id="@+id/crop_transparent_left"
    android:bottom="110dp"
    android:right="1000dp"
    android:top="110dp">
    <shape android:shape="rectangle" >
        <solid android:color="#AA0A0A0A" />
    </shape>
</item>

<!-- This is a border -->
<item
    android:id="@+id/crop_frame"
    android:bottom="100dp"
    android:left="10dp"
    android:right="10dp"
    android:top="100dp">
    <nine-patch android:src="@drawable/img_border" />
</item>

</layer-list>

我不熟悉drawable。我正在做的是绘制4个不同的盒子，一个在顶部和底部，另外两个用于框架。

这是正确的方法，还是可以用更少的代码完成？

重要的是要注意我将支持动态形状的框架，所以我最终将改变Java代码中的值。

感谢您的帮助。

Answer 1

我能用代码执行此操作：

private Drawable createBackground(int widthForRatio, int heightForRatio, int displayWidth, int displayHeight) {

    Bitmap b = BitmapFactory.decodeResource(getResources(), R.drawable.img_border);

    NinePatchDrawable frame = new NinePatchDrawable(getResources(), b, b.getNinePatchChunk(), new Rect(), null);

    Drawable[] layers = { getTransparent(), getTransparent(), getTransparent(), getTransparent(), frame };
    LayerDrawable layerDrawable = new LayerDrawable(layers);

    final TypedArray styledAttributes = getTheme().obtainStyledAttributes(new int[] { android.R.attr.actionBarSize });
    int mActionBarSize = (int) styledAttributes.getDimension(0, 0);
    styledAttributes.recycle();

    layerDrawable.setLayerInset(0, 0, 0, 0, displayHeight - 100 - mActionBarSize);
    layerDrawable.setLayerInset(1, 0, displayHeight - 100 - mActionBarSize, 0, 0);
    layerDrawable.setLayerInset(2, displayWidth - 50, 100, 0, 100);
    layerDrawable.setLayerInset(3, 0, 100, displayWidth - 50, 100);
    layerDrawable.setLayerInset(4, 50, 100, 50, 100);

    return layerDrawable;
}

private ShapeDrawable getTransparent() {
    ShapeDrawable transparent = new ShapeDrawable();
    transparent.getPaint().setColor(Color.parseColor("#AA0A0A0A"));
    return transparent;
}