Add alpha animation for ImageView

app/src/main/java/com/hippo/ehviewer/gallery/gl/ImageView.java

@@ -20,6 +20,8 @@ import android.graphics.Rect;
 import android.graphics.RectF;
 import android.support.annotation.IntDef;
 
+import com.hippo.anani.AnimationUtils;
+import com.hippo.gl.anim.AlphaAnimation;
 import com.hippo.gl.glrenderer.GLCanvas;
 import com.hippo.gl.glrenderer.Texture;
 import com.hippo.gl.view.GLView;
@@ -56,6 +58,8 @@ public class ImageView extends GLView {
     public static final int START_POSITION_BOTTOM_RIGHT = 3;
     public static final int START_POSITION_CENTER = 4;
 
+    private static final long ALPHA_ANIMATION_DURING = 300L;
+
     private Texture mTexture;
     private int mTextureWidth;
     private int mTextureHeight;
@@ -74,6 +78,14 @@ public class ImageView extends GLView {
     private boolean mScaleOffsetDirty = true;
     private boolean mPositionInRootDirty = true;
 
+    private final AlphaAnimation mAlphaAnimation;
+
+    public ImageView() {
+        mAlphaAnimation = new AlphaAnimation(0.0f, 1.0f);
+        mAlphaAnimation.setDuration(ALPHA_ANIMATION_DURING);
+        mAlphaAnimation.setInterpolator(AnimationUtils.FAST_SLOW_INTERPOLATOR);
+    }
+
     @Scale
     public static int sanitizeScaleMode(int scaleMode) {
         if (scaleMode != SCALE_ORIGIN &&
@@ -193,6 +205,11 @@ public class ImageView extends GLView {
             if (mTextureHeight <= 0) {
                 mTextureHeight = 1;
             }
+
+            // Start alpha animation
+            if (isAttachedToRoot()) {
+                startAnimation(mAlphaAnimation, true);
+            }
         } else {
             mTextureWidth = 1;
             mTextureHeight = 1;

app/src/main/java/com/hippo/ehviewer/gallery/gl/PagerLayoutManager.java

@@ -361,20 +361,20 @@ public class PagerLayoutManager extends GalleryView.LayoutManager {
             // Ensure pages
             if (mCurrent == null) {
                 mCurrent = obtainPage();
-                adapter.bind(mCurrent, index);
                 galleryView.addComponent(mCurrent);
+                adapter.bind(mCurrent, index);
             }
             if (mPrevious == null && index > 0) {
                 mPrevious = obtainPage();
-                adapter.bind(mPrevious, index - 1);
                 galleryView.addComponent(mPrevious);
+                adapter.bind(mPrevious, index - 1);
             } else if (mPrevious != null && index == 0) {
                 removePage(mPrevious);
             }
             if (mNext == null && index < size - 1) {
                 mNext = obtainPage();
-                adapter.bind(mNext, index + 1);
                 galleryView.addComponent(mNext);
+                adapter.bind(mNext, index + 1);
             } else if (mNext != null && index == size - 1) {
                 removePage(mNext);
             }
@@ -480,8 +480,8 @@ public class PagerLayoutManager extends GalleryView.LayoutManager {
 
         if (mIndex > 0) {
             mPrevious = obtainPage();
-            mAdapter.bind(mPrevious, mIndex - 1);
             mGalleryView.addComponent(mPrevious);
+            mAdapter.bind(mPrevious, mIndex - 1);
         }
     }
 
@@ -502,8 +502,8 @@ public class PagerLayoutManager extends GalleryView.LayoutManager {
 
         if (mIndex < size - 1) {
             mNext = obtainPage();
-            adapter.bind(mNext, mIndex + 1);
             mGalleryView.addComponent(mNext);
+            adapter.bind(mNext, mIndex + 1);
         }
     }
 

app/src/main/java/com/hippo/ehviewer/gallery/gl/ScrollLayoutManager.java

@@ -192,8 +192,8 @@ public class ScrollLayoutManager extends GalleryView.LayoutManager {
             mIndex--;
 
             GalleryPageView page = obtainPage();
-            mAdapter.bind(page, mIndex);
             galleryView.addComponent(page);
+            mAdapter.bind(page, mIndex);
             mPages.add(0, page);
 
             // Add interval
@@ -239,8 +239,8 @@ public class ScrollLayoutManager extends GalleryView.LayoutManager {
                 pages = null;
                 // New page
                 page = obtainPage();
-                mAdapter.bind(page, index);
                 galleryView.addComponent(page);
+                mAdapter.bind(page, index);
                 mPages.add(page);
             } else {
                 page = pages.next();

app/src/main/java/com/hippo/gl/glrenderer/GLES20Canvas.java

@@ -16,6 +16,7 @@
 package com.hippo.gl.glrenderer;
 
 import android.graphics.Bitmap;
+import android.graphics.Color;
 import android.graphics.Rect;
 import android.graphics.RectF;
 import android.opengl.GLES20;
@@ -838,9 +839,11 @@ public class GLES20Canvas implements GLCanvas {
         setAlpha(textureAlpha);
         drawTexture(texture, source, target);
 
-        float colorAlpha = cappedRatio * currentAlpha;
-        setAlpha(colorAlpha);
-        fillRect(target.left, target.top, target.width(), target.height(), toColor);
+        if (0 != Color.alpha(toColor)) {
+            float colorAlpha = cappedRatio * currentAlpha;
+            setAlpha(colorAlpha);
+            fillRect(target.left, target.top, target.width(), target.height(), toColor);
+        }
 
         restore();
     }

app/src/main/java/com/hippo/gl/view/GLView.java

@@ -153,6 +153,21 @@ public class GLView implements TouchOwner {
     private OnClickListener mOnClickListener;
     private OnLongClickListener mOnLongClickListener;
 
+    public void startAnimation(CanvasAnimation animation, boolean atOnce) {
+        GLRoot root = getGLRoot();
+        if (root == null) throw new IllegalStateException();
+        mAnimation = animation;
+        if (mAnimation != null) {
+            mAnimation.start();
+            if (atOnce) {
+                mAnimation.setStartTime(AnimationTime.get());
+            } else {
+                root.registerLaunchedAnimation(mAnimation);
+            }
+        }
+        invalidate();
+    }
+
     /**
      * Set the enabled state of this view.
      *