camera/app/CameraAppUI.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.app;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Matrix;
import android.graphics.SurfaceTexture;
import android.util.Log;
import android.view.GestureDetector;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.TextureView;
import android.view.View;
import android.view.ViewConfiguration;
import android.widget.FrameLayout;
import android.widget.ImageView;

import com.android.camera.AnimationManager;
import com.android.camera.widget.FilmstripLayout;
import com.android.camera.ui.MainActivityLayout;
import com.android.camera.ui.ModeListView;
import com.android.camera.ui.ModeTransitionView;
import com.android.camera.ui.PreviewOverlay;
import com.android.camera.ui.PreviewStatusListener;
import com.android.camera2.R;

/**
 * CameraAppUI centralizes control of views shared across modules. Whereas module
 * specific views will be handled in each Module UI. For example, we can now
 * bring the flash animation and capture animation up from each module to app
 * level, as these animations are largely the same for all modules.
 *
 * This class also serves to disambiguate touch events. It recognizes all the
 * swipe gestures that happen on the preview by attaching a touch listener to
 * a full-screen view on top of preview TextureView. Since CameraAppUI has knowledge
 * of how swipe from each direction should be handled, it can then redirect these
 * events to appropriate recipient views.
 */
public class CameraAppUI implements ModeListView.ModeSwitchListener,
        TextureView.SurfaceTextureListener {
    private final static String TAG = "CameraAppUI";

    private final AppController mController;
    private final boolean mIsCaptureIntent;
    private final boolean mIsSecureCamera;
    private final AnimationManager mAnimationManager;

    // Swipe states:
    private final static int IDLE = 0;
    private final static int SWIPE_UP = 1;
    private final static int SWIPE_DOWN = 2;
    private final static int SWIPE_LEFT = 3;
    private final static int SWIPE_RIGHT = 4;

    // Touch related measures:
    private final int mSlop;
    private final static int SWIPE_TIME_OUT_MS = 500;

    private final static int SHIMMY_DELAY_MS = 1000;

    // Mode cover states:
    private final static int COVER_HIDDEN = 0;
    private final static int COVER_SHOWN = 1;
    private final static int COVER_WILL_HIDE_AT_NEXT_FRAME = 2;

    // App level views:
    private final FrameLayout mCameraRootView;
    private final ModeTransitionView mModeTransitionView;
    private final MainActivityLayout mAppRootView;
    private final ModeListView mModeListView;
    private final FilmstripLayout mFilmstripLayout;
    private TextureView mTextureView;
    private View mFlashOverlay;
    private FrameLayout mModuleUI;

    private GestureDetector mGestureDetector;
    private int mSwipeState = IDLE;
    private ImageView mPreviewThumbView;
    private PreviewOverlay mPreviewOverlay;
    private PreviewStatusListener mPreviewStatusListener;
    private int mModeCoverState = COVER_HIDDEN;

    public interface AnimationFinishedListener {
        public void onAnimationFinished(boolean success);
    }

    private class MyTouchListener implements View.OnTouchListener {
        private boolean mScaleStarted = false;
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            if (event.getActionMasked() == MotionEvent.ACTION_DOWN) {
                mScaleStarted = false;
            } else if (event.getActionMasked() == MotionEvent.ACTION_POINTER_DOWN) {
                mScaleStarted = true;
            }
            return (!mScaleStarted) && mGestureDetector.onTouchEvent(event);
        }
    }

    /**
     * This gesture listener finds out the direction of the scroll gestures and
     * sends them to CameraAppUI to do further handling.
     */
    private class MyGestureListener extends GestureDetector.SimpleOnGestureListener {
        private MotionEvent mDown;

        @Override
        public boolean onScroll(MotionEvent e1, MotionEvent ev, float distanceX, float distanceY) {
            if (ev.getEventTime() - ev.getDownTime() > SWIPE_TIME_OUT_MS
                    || mSwipeState != IDLE) {
                return true;
            }

            int deltaX = (int) (ev.getX() - mDown.getX());
            int deltaY = (int) (ev.getY() - mDown.getY());
            if (ev.getActionMasked() == MotionEvent.ACTION_MOVE) {
                if (Math.abs(deltaX) > mSlop || Math.abs(deltaY) > mSlop) {
                    // Calculate the direction of the swipe.
                    if (deltaX >= Math.abs(deltaY)) {
                        // Swipe right.
                        setSwipeState(SWIPE_RIGHT);
                    } else if (deltaX <= -Math.abs(deltaY)) {
                        // Swipe left.
                        setSwipeState(SWIPE_LEFT);
                    } else if (deltaY >= Math.abs(deltaX)) {
                        // Swipe down.
                        setSwipeState(SWIPE_DOWN);
                    } else if (deltaY <= -Math.abs(deltaX)) {
                        // Swipe up.
                        setSwipeState(SWIPE_UP);
                    }
                }
            }
            return true;
        }

        private void setSwipeState(int swipeState) {
            mSwipeState = swipeState;
            // Notify new swipe detected.
            onSwipeDetected(swipeState);
        }

        @Override
        public boolean onDown(MotionEvent ev) {
            mDown = MotionEvent.obtain(ev);
            mSwipeState = IDLE;
            return false;
        }
    }

    public CameraAppUI(AppController controller, MainActivityLayout appRootView,
                       boolean isSecureCamera, boolean isCaptureIntent) {
        mSlop = ViewConfiguration.get(controller.getAndroidContext()).getScaledTouchSlop();
        mController = controller;
        mIsSecureCamera = isSecureCamera;
        mIsCaptureIntent = isCaptureIntent;

        mAppRootView = appRootView;
        mFilmstripLayout = (FilmstripLayout) appRootView.findViewById(R.id.filmstrip_layout);
        mCameraRootView = (FrameLayout) appRootView.findViewById(R.id.camera_app_root);
        mModeTransitionView = (ModeTransitionView)
                mAppRootView.findViewById(R.id.mode_transition_view);
        mGestureDetector = new GestureDetector(controller.getAndroidContext(),
                new MyGestureListener());
        mModeListView = (ModeListView) appRootView.findViewById(R.id.mode_list_layout);
        if (mModeListView != null) {
            mModeListView.setModeSwitchListener(this);
        } else {
            Log.e(TAG, "Cannot find mode list in the view hierarchy");
        }
        mAnimationManager = new AnimationManager();
    }

    /**
     * Redirects touch events to appropriate recipient views based on swipe direction.
     * More specifically, swipe up and swipe down will be handled by the view that handles
     * mode transition; swipe left will be send to filmstrip; swipe right will be redirected
     * to mode list in order to bring up mode list.
     */
    private void onSwipeDetected(int swipeState) {
        if (swipeState == SWIPE_UP || swipeState == SWIPE_DOWN) {
            // Quick switch between photo/video.
            if (mController.getCurrentModuleIndex() == ModeListView.MODE_PHOTO ||
                    mController.getCurrentModuleIndex() == ModeListView.MODE_VIDEO) {
                mAppRootView.redirectTouchEventsTo(mModeTransitionView);

                final int moduleToTransitionTo =
                        mController.getCurrentModuleIndex() == ModeListView.MODE_PHOTO ?
                        ModeListView.MODE_VIDEO : ModeListView.MODE_PHOTO;
                int shadeColorId = ModeListView.getModeThemeColor(moduleToTransitionTo);
                int iconRes = ModeListView.getModeIconResourceId(moduleToTransitionTo);

                AnimationFinishedListener listener = new AnimationFinishedListener() {
                    public void onAnimationFinished(boolean success) {
                        if (success) {
                            // Go to new module when the previous operation is successful.
                            mController.onModeSelected(moduleToTransitionTo);
                            mModeTransitionView.startPeepHoleAnimation();
                        }
                    }
                };
                if (mSwipeState == SWIPE_UP) {
                    mModeTransitionView.prepareToPullUpShade(shadeColorId, iconRes, listener);
                } else {
                    mModeTransitionView.prepareToPullDownShade(shadeColorId, iconRes, listener);
                }
            }
        } else if (swipeState == SWIPE_LEFT) {
            // Pass the touch sequence to filmstrip layout.
            mAppRootView.redirectTouchEventsTo(mFilmstripLayout);

        } else if (swipeState == SWIPE_RIGHT) {
            // Pass the touch to mode switcher
            mAppRootView.redirectTouchEventsTo(mModeListView);
        }
    }

    /**
     * Gets called when activity resumes in preview.
     */
    public void resume() {
        if (mTextureView == null || mTextureView.getSurfaceTexture() != null) {
            mModeListView.startAccordionAnimationWithDelay(SHIMMY_DELAY_MS);
        } else {
            // Show mode theme cover until preview is ready
            showModeCoverUntilPreviewReady();
        }
    }

    /**
     * A cover view showing the mode theme color and mode icon will be visible on
     * top of preview until preview is ready (i.e. camera preview is started and
     * the first frame has been received).
     */
    private void showModeCoverUntilPreviewReady() {
        int modeId = mController.getCurrentModuleIndex();
        int colorId = ModeListView.getModeThemeColor(modeId);
        int iconId = ModeListView.getModeIconResourceId(modeId);
        mModeTransitionView.setupModeCover(colorId, iconId);
        mModeCoverState = COVER_SHOWN;
    }

    private void hideModeCover() {
        mModeTransitionView.hideModeCover(new AnimationFinishedListener() {
            @Override
            public void onAnimationFinished(boolean success) {
                if (success) {
                    // Show shimmy in SHIMMY_DELAY_MS
                    mModeListView.startAccordionAnimationWithDelay(SHIMMY_DELAY_MS);
                }
            }
        });
    }

    /**
     * Called when the back key is pressed.
     *
     * @return Whether the UI responded to the key event.
     */
    public boolean onBackPressed() {
        return mFilmstripLayout.onBackPressed();
    }

    /**
     * Sets a {@link com.android.camera.ui.PreviewStatusListener} that
     * listens to SurfaceTexture changes. In addition, the listener will also provide
     * a {@link android.view.GestureDetector.OnGestureListener}, which will listen to
     * gestures that happen on camera preview.
     *
     * @param previewStatusListener the listener that gets notified when SurfaceTexture
     *                              changes
     */
    public void setPreviewStatusListener(PreviewStatusListener previewStatusListener) {
        mPreviewStatusListener = previewStatusListener;
        if (mPreviewStatusListener != null) {
            GestureDetector.OnGestureListener gestureListener
                    = mPreviewStatusListener.getGestureListener();
            if (gestureListener != null) {
                mPreviewOverlay.setGestureListener(gestureListener);
            }
        }
    }

    /**
     * This inflates generic_module layout, which contains all the shared views across
     * modules. Then each module inflates their own views in the given view group. For
     * now, this is called every time switching from a not-yet-refactored module to a
     * refactored module. In the future, this should only need to be done once per app
     * start.
     */
    public void prepareModuleUI() {
        mCameraRootView.removeAllViews();
        LayoutInflater inflater = (LayoutInflater) mController.getAndroidContext()
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        inflater.inflate(R.layout.generic_module, mCameraRootView, true);

        mModuleUI = (FrameLayout) mCameraRootView.findViewById(R.id.module_layout);
        mTextureView = (TextureView) mCameraRootView.findViewById(R.id.preview_content);
        mTextureView.setSurfaceTextureListener(this);
        mPreviewOverlay = (PreviewOverlay) mCameraRootView.findViewById(R.id.preview_overlay);
        mPreviewOverlay.setOnTouchListener(new MyTouchListener());
        mFlashOverlay = mCameraRootView.findViewById(R.id.flash_overlay);
        mPreviewThumbView = (ImageView) mCameraRootView.findViewById(R.id.preview_thumb);

    }

    // TODO: Remove this when refactor is done.
    // This is here to ensure refactored modules can work with not-yet-refactored ones.
    public void clearCameraUI() {
        mCameraRootView.removeAllViews();
        mModuleUI = null;
        mTextureView = null;
        mPreviewOverlay = null;
        mFlashOverlay = null;
    }

    /**
     * Called indirectly from each module in their initialization to get a view group
     * to inflate the module specific views in.
     *
     * @return a view group for modules to attach views to
     */
    public FrameLayout getModuleRootView() {
        // TODO: Change it to mModuleUI when refactor is done
        return mCameraRootView;
    }

    /**
     * Remove all the module specific views.
     */
    public void clearModuleUI() {
        if (mModuleUI != null) {
            mModuleUI.removeAllViews();
        }

        // TODO: Bring TextureView up to the app level
        mTextureView.removeOnLayoutChangeListener(null);

        mPreviewStatusListener = null;
        mPreviewOverlay.reset();
    }

    /**
     * Gets called when preview is started.
     */
    public void onPreviewStarted() {
        if (mModeCoverState == COVER_SHOWN) {
            mModeCoverState = COVER_WILL_HIDE_AT_NEXT_FRAME;
        }
    }

    @Override
    public void onModeSelected(int modeIndex) {
        mController.onModeSelected(modeIndex);
    }

    /**
     * Sets the transform matrix on the preview TextureView
     */
    public void setPreviewTransformMatrix(Matrix transformMatrix) {
        if (mTextureView == null) {
            throw new UnsupportedOperationException("Cannot set transform matrix on a null" +
                    " TextureView");
        }
        mTextureView.setTransform(transformMatrix);
    }


    /********************** Capture animation **********************/
    /* TODO: This session is subject to UX changes. In addition to the generic
       flash animation and post capture animation, consider designating a parameter
       for specifying the type of animation, as well as an animation finished listener
       so that modules can have more knowledge of the status of the animation. */

    /**
     * Starts the pre-capture animation.
     */
    public void startPreCaptureAnimation() {
        mAnimationManager.startFlashAnimation(mFlashOverlay);
    }

    /**
     * Cancels the pre-capture animation.
     */
    public void cancelPreCaptureAnimation() {
        mAnimationManager.cancelAnimations();
    }

    /**
     * Starts the post-capture animation with the current preview image.
     */
    public void startPostCaptureAnimation() {
        if (mTextureView == null) {
            Log.e(TAG, "Cannot get a frame from a null TextureView for animation");
            return;
        }
        // TODO: Down sample bitmap
        startPostCaptureAnimation(mTextureView.getBitmap());
    }

    /**
     * Starts the post-capture animation with the given thumbnail.
     *
     * @param thumbnail The thumbnail for the animation.
     */
    public void startPostCaptureAnimation(Bitmap thumbnail) {
        mPreviewThumbView.setImageBitmap(thumbnail);
        mAnimationManager.startCaptureAnimation(mPreviewThumbView);
    }

    /**
     * Cancels the post-capture animation.
     */
    public void cancelPostCaptureAnimation() {
        mAnimationManager.cancelAnimations();
    }

    /***************************SurfaceTexture Listener*********************************/

    @Override
    public void onSurfaceTextureAvailable(SurfaceTexture surface, int width, int height) {
        Log.v(TAG, "SurfaceTexture is available");
        if (mPreviewStatusListener != null) {
            mPreviewStatusListener.onSurfaceTextureAvailable(surface, width, height);
        }
    }

    @Override
    public void onSurfaceTextureSizeChanged(SurfaceTexture surface, int width, int height) {
        if (mPreviewStatusListener != null) {
            mPreviewStatusListener.onSurfaceTextureSizeChanged(surface, width, height);
        }
    }

    @Override
    public boolean onSurfaceTextureDestroyed(SurfaceTexture surface) {
        Log.v(TAG, "SurfaceTexture is destroyed");
        if (mPreviewStatusListener != null) {
            return mPreviewStatusListener.onSurfaceTextureDestroyed(surface);
        }
        return false;
    }

    @Override
    public void onSurfaceTextureUpdated(SurfaceTexture surface) {
        if (mModeCoverState == COVER_WILL_HIDE_AT_NEXT_FRAME) {
            hideModeCover();
            mModeCoverState = COVER_HIDDEN;
        }
        if (mPreviewStatusListener != null) {
            mPreviewStatusListener.onSurfaceTextureUpdated(surface);
        }
    }
}