xref: /packages/apps/Camera2/src/com/android/camera/ui/PreviewStatusListener.java

/*
 * Copyright (C) 2013 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.camera.ui;

import android.graphics.RectF;
import android.view.GestureDetector;
import android.view.TextureView;
import android.view.View;

/**
 * This interface defines a listener that watches preview status, including SurfaceTexture
 * change and preview gestures.
 */
public interface PreviewStatusListener extends TextureView.SurfaceTextureListener {
    /**
     * The preview status listener needs to provide an
     * {@link android.view.GestureDetector.OnGestureListener} in order to listen
     * to the touch events that happen on preview.
     *
     * @return a listener that listens to touch events
     */
    public GestureDetector.OnGestureListener getGestureListener();

    /**
     * An {@link android.view.View.OnTouchListener} can be provided in addition to
     * or instead of a {@link android.view.GestureDetector.OnGestureListener}
     * for listening to touch events on the preview.  The listener is called whenever
     * there is a touch event on the {@link com.android.camera.ui.PreviewOverlay}.
     */
    public View.OnTouchListener getTouchListener();

    /**
     * Gets called when preview TextureView gets a layout change call.
     */
    public void onPreviewLayoutChanged(View v, int left, int top, int right,
            int bottom, int oldLeft, int oldTop, int oldRight, int oldBottom);

    /**
     * This listener gets notified when the actual preview frame changes due
     * to a transform matrix being applied to the TextureView
     */
    public interface PreviewAreaChangedListener {
        public void onPreviewAreaChanged(RectF previewArea);
    }

    /**
     * The preview status listener needs to know for the specific module whether
     * preview TextureView should automatically adjust its transform matrix based
     * on the current aspect ratio, width and height of the TextureView.
     *
     * @return whether transform matrix should be automatically adjusted
     */
    public boolean shouldAutoAdjustTransformMatrixOnLayout();

    /**
     * Gets called when the preview is flipped (i.e. 180-degree rotated).
     */
    public void onPreviewFlipped();

    /**
     * This listener gets notified when the preview aspect ratio is changed.
     */
    public interface PreviewAspectRatioChangedListener {
        public void onPreviewAspectRatioChanged(float aspectRatio);
    }
}