ZoomSurfaceView

A SurfaceView implementation (extending GLSurfaceView) that supports panning and zooming of its contents through OpenGL rendering. You can use this for video streaming, camera previews or any other surface application that streams image buffers into a Surface.

<com.otaliastudios.zoom.ZoomSurfaceView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:transformation="centerInside"
    app:transformationGravity="auto"
    app:alignment="center"
    app:overScrollHorizontal="false"
    app:overScrollVertical="false"
    app:overPinchable="false"
    app:horizontalPanEnabled="true"
    app:verticalPanEnabled="true"
    app:zoomEnabled="true"
    app:flingEnabled="true"
    app:scrollEnabled="true"
    app:oneFingerScrollEnabled="true"
    app:twoFingersScrollEnabled="true"
    app:threeFingersScrollEnabled="true"
    app:minZoom="1"
    app:minZoomType="zoom"
    app:maxZoom="2.5"
    app:maxZoomType="zoom"
    app:animationDuration="280"/>

Setup

There are a few special things about ZoomSurfaceView with respect to the other classes:

• It requires API level 18
• It will not draw scrollbars
• You must either call ZoomSurfaceView.setContentSize() passing the stream size, or measure the view so that it matches the stream aspect ratio.

Starting from v1.7.1, you do not need to add the Egloo dependency in order to use ZoomSurfaceView.

Usage

Using Surfaces is not a simple topic so we won’t go into details here. Please take a look at the demo app which reproduces a zoomable/pannable video through ExoPlayer.

To get a usable Surface out of ZoomSurfaceView, please add a callback and wait for the surface to be available:

ZoomSurfaceView surfaceView = findViewById(R.id.zoom_surface_view);
surfaceView.addCallback(new ZoomSurfaceView.Callback() {
    @Override
    public void onZoomSurfaceCreated(@NotNull ZoomSurfaceView view) {
        Surface surface = view.getSurface();
        // Use this surface for video players, camera preview, ...
    }

    @Override
    public void onZoomSurfaceDestroyed(@NotNull ZoomSurfaceView view) { }
});

APIs

The ZoomSurfaceView will forward all API calls to the internal engine: see zoom, pan and low level engine documentation. You can also get the backing engine using zoomSurfaceView.getEngine().

zoomSurfaceView.panTo(x, y, true); // Shorthand for zoomSurfaceView.getEngine().panTo(x, y, true)
zoomSurfaceView.panBy(deltaX, deltaY, true);
zoomSurfaceView.zoomTo(zoom, true);
zoomSurfaceView.zoomBy(factor, true);
zoomSurfaceView.realZoomTo(realZoom, true);
zoomSurfaceView.moveTo(zoom, x, y, true);