调整图像加载过渡效果

src/com/hippo/ehviewer/ImageLoader.java

@@ -50,7 +50,7 @@ public class ImageLoader {
     private final ImageCache mImageCache;
     private final ImageDownloader mImageDownloader;
 
-    public ImageLoader(Context context) {
+    private ImageLoader(Context context) {
         mLoadTasks = new Stack<LoadTask>();
         mImageDownloader = new ImageDownloader();
 

src/com/hippo/ehviewer/effect/DrawableTransition.java

@@ -0,0 +1,115 @@
+/*
+ * Copyright (C) 2014 Hippo Seven
+ *
+ * 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.hippo.ehviewer.effect;
+
+import android.animation.ObjectAnimator;
+import android.animation.TypeEvaluator;
+import android.animation.ValueAnimator;
+import android.graphics.ColorMatrix;
+import android.graphics.ColorMatrixColorFilter;
+import android.graphics.drawable.Drawable;
+
+public class DrawableTransition {
+
+    public static void transit(final Drawable drawable, boolean fromDark, long duration) {
+        AlphaSatColorMatrixEvaluator evaluator = new AlphaSatColorMatrixEvaluator(fromDark);
+        final AnimateColorMatrixColorFilter filter = new AnimateColorMatrixColorFilter(evaluator.getColorMatrix());
+        drawable.setColorFilter(filter.getColorFilter());
+
+        ObjectAnimator animator = ObjectAnimator.ofObject(filter, "colorMatrix", evaluator,
+                evaluator.getColorMatrix());
+        animator.addUpdateListener( new ValueAnimator.AnimatorUpdateListener() {
+            @Override
+            public void onAnimationUpdate(ValueAnimator animation) {
+                drawable.setColorFilter (filter.getColorFilter());
+            }
+        });
+        animator.setDuration(duration);
+        animator.start();
+    }
+
+    // From rnr.tests.imageloadingpattern.MainActivity.AnimateColorMatrixColorFilter
+    /// Thanks to @DavidCrawford \
+    /// see http://stackoverflow.com/a/27301389/2573335
+    private static class AnimateColorMatrixColorFilter {
+        private ColorMatrixColorFilter mFilter;
+        private ColorMatrix mMatrix;
+
+        public AnimateColorMatrixColorFilter(ColorMatrix matrix) {
+            setColorMatrix(matrix);
+        }
+
+        public ColorMatrixColorFilter getColorFilter() {
+            return mFilter;
+        }
+
+        public void setColorMatrix(ColorMatrix matrix) {
+            mMatrix = matrix;
+            mFilter = new ColorMatrixColorFilter(matrix);
+        }
+
+        public ColorMatrix getColorMatrix() {
+            return mMatrix;
+        }
+    }
+
+    // From rnr.tests.imageloadingpattern.AlphaSatColorMatrixEvaluator
+    // with modification
+    private static class AlphaSatColorMatrixEvaluator implements TypeEvaluator {
+        private final ColorMatrix colorMatrix;
+        private final float[] elements = new float[20];
+        private final boolean mFromDark;
+
+        public AlphaSatColorMatrixEvaluator(boolean fromDark) {
+            colorMatrix = new ColorMatrix ();
+            mFromDark = fromDark;
+        }
+
+        public ColorMatrix getColorMatrix() {
+            return colorMatrix;
+        }
+
+        @Override
+        public Object evaluate(float fraction, Object startValue, Object endValue) {
+            // There are 4 phases so we multiply fraction by that amount
+            float phase = fraction * 4;
+
+            // Compute the alpha change over period [0, 2]
+            float alpha = Math.min(phase, 2.0f) / 2.0f;
+            elements [19] = Math.round(alpha * 255);
+
+            // We substract to make the picture look darker, it will automatically clamp
+            // This is spread over period [0, 3]
+            final int MaxBlacker = 50;
+            float blackening = Math.round((1 - Math.min(phase, 3.0f) / 3.0f) * MaxBlacker);
+            elements [4] = elements [9] = elements [14] = mFromDark ? -blackening : blackening;
+
+            // Finally we desaturate over [0, 4], taken from ColorMatrix.SetSaturation
+            float invSat = 1 - Math.max(0.2f, fraction);
+            float R = 0.213f * invSat;
+            float G = 0.715f * invSat;
+            float B = 0.072f * invSat;
+
+            elements[0] = R + fraction; elements[1] = G;            elements[2] = B;
+            elements[5] = R;            elements[6] = G + fraction; elements[7] = B;
+            elements[10] = R;           elements[11] = G;           elements[12] = B + fraction;
+
+            colorMatrix.set(elements);
+            return colorMatrix;
+        }
+    }
+}

src/com/hippo/ehviewer/widget/LoadImageView.java

@@ -18,16 +18,14 @@ package com.hippo.ehviewer.widget;
 
 import android.content.Context;
 import android.graphics.Bitmap;
-import android.graphics.drawable.BitmapDrawable;
 import android.graphics.drawable.Drawable;
-import android.graphics.drawable.TransitionDrawable;
 import android.util.AttributeSet;
 import android.view.View;
 import android.widget.ImageView;
 
 import com.hippo.ehviewer.ImageLoader;
 import com.hippo.ehviewer.R;
-import com.hippo.ehviewer.util.Ui;
+import com.hippo.ehviewer.effect.DrawableTransition;
 
 public class LoadImageView extends FixedAspectImageView {
     @SuppressWarnings("unused")
@@ -38,11 +36,8 @@ public class LoadImageView extends FixedAspectImageView {
     public static final int LOADED = 0x2;
     public static final int FAIL = 0x3;
 
-    private static final int WAIT_IMAGE_ID = R.drawable.ic_launcher;
     private static final int TOUCH_IMAGE_ID = R.drawable.ic_touch;
 
-    private static final int DURATION = 300;
-
     private int mState = NONE;
 
     private String mUrl;
@@ -93,10 +88,6 @@ public class LoadImageView extends FixedAspectImageView {
         return mState;
     }
 
-    public void setWaitImage() {
-        setImageResource(WAIT_IMAGE_ID);
-    }
-
     public void setTouchImage() {
         setImageResource(TOUCH_IMAGE_ID);
     }
@@ -106,21 +97,9 @@ public class LoadImageView extends FixedAspectImageView {
      * @param bmp
      */
     public void setContextImage(Bitmap bmp) {
-
-        Drawable[] layers = new Drawable[2];
-        layers[0] = Ui.transparentDrawable;
-        layers[1] = new BitmapDrawable(getContext().getResources(), bmp);
-        TransitionDrawable transitionDrawable = new TransitionDrawable(layers);
-        setImageDrawable(transitionDrawable);
-        transitionDrawable.startTransition(DURATION);
-
-        // I get no idea which is better
-        /*
         setImageBitmap(bmp);
-        AlphaAnimation aa = new AlphaAnimation(0.0f,1.0f);
-        aa.setDuration(DURATION);
-        startAnimation(aa);
-        */
+        final Drawable drawable = getDrawable();
+        DrawableTransition.transit(drawable, false, 1000);
     }
 
     public static class SimpleImageGetListener