add a simple photo flipper dream.

Change-Id: I33a5dc491445ba6203e744099187df2760486be6

1 files changed, 206 insertions, 0 deletions

diff --git a/src/com/android/dreams/phototable/PhotoCarousel.java b/src/com/android/dreams/phototable/PhotoCarousel.java
new file mode 100644
index 0000000..62a44f5
--- /dev/null
+++ b/src/com/android/dreams/phototable/PhotoCarousel.java
@@ -0,0 +1,206 @@
+/*
+ * Copyright (C) 2012 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.dreams.phototable;
+
+import android.content.Context;
+import android.content.res.Resources;
+import android.graphics.Bitmap;
+import android.graphics.BitmapFactory;
+import android.os.AsyncTask;
+import android.service.dreams.Dream;
+import android.util.AttributeSet;
+import android.util.Log;
+import android.view.GestureDetector;
+import android.view.MotionEvent;
+import android.view.View;
+import android.view.ViewPropertyAnimator;
+import android.widget.FrameLayout;
+import android.widget.ImageView;
+
+/**
+ * A FrameLayout that holds two photos, back to back.
+ */
+public class PhotoCarousel extends FrameLayout {
+    private static final String TAG = "PhotoCarousel";
+
+    private final Flipper mFlipper;
+    private final LocalSource mLocalSource;
+    private final StockSource mStockSource;
+    private final GestureDetector mGestureDetector;
+    private final View[] mPanel;
+    private final BitmapFactory.Options mOptions;
+    private final int mFlipDuration;
+    private final int mDropPeriod;
+    private boolean mOnce;
+    private int mLongSide;
+    private int mShortSide;
+
+    class Flipper implements Runnable {
+        @Override
+        public void run() {
+            PhotoCarousel.this.flip(1f);
+        }
+    }
+
+    public PhotoCarousel(Context context, AttributeSet as) {
+        super(context, as);
+        final Resources resources = getResources();
+        mDropPeriod = resources.getInteger(R.integer.drop_period);
+        mFlipDuration = resources.getInteger(R.integer.flip_duration);
+        mOptions = new BitmapFactory.Options();
+        mOptions.inTempStorage = new byte[32768];
+        mLocalSource = new LocalSource(context);
+        mStockSource = new StockSource(context);
+        mPanel = new View[2];
+        mFlipper = new Flipper();
+        mGestureDetector = new GestureDetector(context,
+                new GestureDetector.SimpleOnGestureListener() {
+                    @Override
+                    public boolean onFling(MotionEvent e1, MotionEvent e2, float vX, float vY) {
+                        Log.i(TAG, "fling with " + vX);
+                        flip(Math.signum(vX));
+                        return true;
+                    }
+                });
+    }
+
+    private float lockTo180(float a) {
+        return 180f * (float) Math.floor(a / 180f);
+    }
+
+    private float wrap360(float a) {
+        return a - 360f * (float) Math.floor(a / 360f);
+    }
+
+    private class PhotoLoadTask extends AsyncTask<Void, Void, Bitmap> {
+        private PhotoCarousel mCarousel;
+        private ImageView mDestination;
+
+        public PhotoLoadTask(PhotoCarousel carousel, View destination) {
+            mCarousel = carousel;
+            mDestination = (ImageView) destination;
+        }
+        @Override
+        public Bitmap doInBackground(Void... unused) {
+            Bitmap decodedPhoto = null;
+            decodedPhoto = mCarousel.mLocalSource.next(mCarousel.mOptions,
+                    mCarousel.mLongSide, mCarousel.mShortSide);
+            if (decodedPhoto == null) {
+                decodedPhoto = mCarousel.mStockSource.next(mCarousel.mOptions,
+                        mCarousel.mLongSide, mCarousel.mShortSide);
+            }
+            return decodedPhoto;
+        }
+
+        @Override
+        public void onPostExecute(Bitmap photo) {
+            if (photo != null) {
+                mDestination.setImageBitmap(photo);
+                mCarousel.requestLayout();
+            }
+        }
+    };
+
+    public void flip(float sgn) {
+        mPanel[0].animate().cancel();
+        mPanel[1].animate().cancel();
+
+        float frontY = mPanel[0].getRotationY();
+        float backY = mPanel[1].getRotationY();
+
+        frontY = wrap360(frontY);
+        backY = wrap360(backY);
+
+        mPanel[0].setRotationY(frontY);
+        mPanel[1].setRotationY(backY);
+
+        frontY = lockTo180(frontY + sgn * 180f);
+        backY = lockTo180(backY + sgn * 180f);
+
+        float frontA = 1f;
+        float backA = 0f;
+        if (frontY == 180f || frontY == -180f) {
+            frontA = 0f;
+            backA = 1f;
+        } else {
+            frontA = 1f;
+            backA = 0f;
+        }
+
+        ViewPropertyAnimator frontAnim = mPanel[0].animate()
+                .rotationY(frontY)
+                .alpha(frontA)
+                .setDuration(mFlipDuration);
+        ViewPropertyAnimator backAnim = mPanel[1].animate()
+                .rotationY(backY)
+                .alpha(backA)
+                .setDuration(mFlipDuration);
+
+        int replaceIdx = 1;
+        ViewPropertyAnimator replaceAnim = backAnim;
+        if (frontA == 0f) {
+            replaceAnim = frontAnim;
+            replaceIdx = 0;
+        }
+
+        final View replaceView = mPanel[replaceIdx];
+        replaceAnim.withEndAction(new Runnable() {
+                @Override
+                public void run() {
+                    new PhotoLoadTask(PhotoCarousel.this, replaceView)
+                            .execute();
+                }
+            });
+
+        frontAnim.start();
+        backAnim.start();
+
+        scheduleNext(mDropPeriod);
+    }
+
+    @Override
+    public void onLayout(boolean changed, int left, int top, int right, int bottom) {
+        super.onLayout(changed, left, top, right, bottom);
+        int height = bottom - top;
+        int width = right - left;
+
+        mLongSide = (int) Math.max(width, height);
+        mShortSide = (int) Math.min(width, height);
+
+        if (!mOnce) {
+            mOnce = true;
+
+            mPanel[0] = findViewById(R.id.front);
+            mPanel[1] = findViewById(R.id.back);
+
+            new PhotoLoadTask(this, mPanel[0]).execute();
+            new PhotoLoadTask(this, mPanel[1]).execute();
+
+            scheduleNext(mDropPeriod);
+        }
+    }
+
+    @Override
+    public boolean onTouchEvent(MotionEvent event) {
+        mGestureDetector.onTouchEvent(event);
+        return true;
+    }
+
+    public void scheduleNext(int delay) {
+        removeCallbacks(mFlipper);
+        postDelayed(mFlipper, delay);
+    }
+}