Improve fling implementation and experience

Update README and CHANGELOG
Update version

Author: barteksc

CHANGELOG.md

@@ -1,3 +1,7 @@
+## 2.6.0 (2017-06-04)
+* Fix fling on single-page documents
+* Greatly improve overall fling experience
+
 ## 2.5.1 (2017-04-08)
 * Temporarily downgrade PdfiumAndroid until #253 will be fixed
 

README.md

@@ -10,16 +10,9 @@ Library for displaying PDF documents on Android, with `animations`, `gestures`,
 It is based on [PdfiumAndroid](https://github.com/barteksc/PdfiumAndroid) for decoding PDF files. Works on API 11 (Android 3.0) and higher.
 Licensed under Apache License 2.0.
 
-## What's new in 2.5.0?
-* Update PdfiumAndroid to 1.6.0, which is based on newest Pdfium from Android 7.1.1. It should fix many rendering and fonts problems
-* Add method `pdfView.fitToWidth()`, which called in `OnRenderListener.onInitiallyRendered()` will fit document to width of the screen (inspired by [1stmetro](https://github.com/1stmetro))
-* Add change from pull request by [isanwenyu](https://github.com/isanwenyu) to get rid of rare IllegalArgumentException while rendering
-* Add `OnRenderListener`, that will be called once, right before document is drawn on the screen
-* Add `Configurator.enableAntialiasing()` to improve rendering on low-res screen a little bit (as suggested by [majkimester](majkimester))
-* Modify engine to not block UI when big documents are loaded
-* Change `Constants` interface and inner interfaces to static public classes, to allow modifying core config values
-
-Version 2.5.1 temporarily downgrades PdfiumAndroid until #253 will be fixed
+## What's new in 2.6.0?
+* Fix fling on single-page documents
+* Greatly improve overall fling experience
 
 ## Changes in 2.0 API
 * `Configurator#defaultPage(int)` and `PDFView#jumpTo(int)` now require page index (i.e. starting from 0)
@@ -34,7 +27,7 @@ Version 2.5.1 temporarily downgrades PdfiumAndroid until #253 will be fixed
 
 Add to _build.gradle_:
 
-`compile 'com.github.barteksc:android-pdf-viewer:2.5.1'`
+`compile 'com.github.barteksc:android-pdf-viewer:2.6.0'`
 
 Library is available in jcenter repository, probably it'll be in Maven Central soon.
 

android-pdf-viewer/build.gradle

@@ -13,7 +13,7 @@ ext {
     siteUrl = 'https://github.com/barteksc/AndroidPdfViewer'
     gitUrl = 'https://github.com/barteksc/AndroidPdfViewer.git'
 
-    libraryVersion = '2.5.1'
+    libraryVersion = '2.6.0'
 
     developerId = 'barteksc'
     developerName = 'Bartosz Schiller'
@@ -32,7 +32,7 @@ android {
         minSdkVersion 11
         targetSdkVersion 25
         versionCode 1
-        versionName "2.5.1"
+        versionName "2.6.0"
     }
 
 }

android-pdf-viewer/src/main/java/com/github/barteksc/pdfviewer/AnimationManager.java

@@ -21,7 +21,7 @@
 import android.animation.ValueAnimator.AnimatorUpdateListener;
 import android.graphics.PointF;
 import android.view.animation.DecelerateInterpolator;
-import android.widget.Scroller;
+import android.widget.OverScroller;
 
 
 /**
@@ -36,13 +36,11 @@ class AnimationManager {
 
     private ValueAnimator animation;
 
-    private Scroller scroller;
-
-    private ValueAnimator flingAnimation;
+    private OverScroller scroller;
 
     public AnimationManager(PDFView pdfView) {
         this.pdfView = pdfView;
-        scroller = new Scroller(pdfView.getContext(), null, true);
+        scroller = new OverScroller(pdfView.getContext());
     }
 
     public void startXAnimation(float xFrom, float xTo) {
@@ -76,13 +74,7 @@ public void startZoomAnimation(float centerX, float centerY, float zoomFrom, flo
 
     public void startFlingAnimation(int startX, int startY, int velocityX, int velocityY, int minX, int maxX, int minY, int maxY) {
         stopAll();
-        flingAnimation = ValueAnimator.ofFloat(0, 1);
-        FlingAnimation flingAnim = new FlingAnimation();
-        flingAnimation.addUpdateListener(flingAnim);
-        flingAnimation.addListener(flingAnim);
         scroller.fling(startX, startY, velocityX, velocityY, minX, maxX, minY, maxY);
-        flingAnimation.setDuration(scroller.getDuration());
-        flingAnimation.start();
     }
 
     public void stopAll() {
@@ -94,11 +86,11 @@ public void stopAll() {
     }
 
     public void stopFling() {
-        if (flingAnimation != null) {
-            scroller.forceFinished(true);
-            flingAnimation.cancel();
-            flingAnimation = null;
-        }
+        scroller.forceFinished(true);
+    }
+
+    public OverScroller getScroller() {
+        return scroller;
     }
 
     class XAnimation implements AnimatorUpdateListener {
@@ -157,38 +149,6 @@ public void onAnimationStart(Animator animation) {
 
     }
 
-    class FlingAnimation implements AnimatorUpdateListener, AnimatorListener {
-        @Override
-        public void onAnimationUpdate(ValueAnimator animation) {
-            if (!scroller.isFinished()) {
-                scroller.computeScrollOffset();
-                pdfView.moveTo(scroller.getCurrX(), scroller.getCurrY());
-                pdfView.loadPageByOffset();
-            }
-        }
-
-        @Override
-        public void onAnimationStart(Animator animation) {
-
-        }
-
-        @Override
-        public void onAnimationEnd(Animator animation) {
-            pdfView.loadPages();
-            hideHandle();
-        }
-
-        @Override
-        public void onAnimationCancel(Animator animation) {
-
-        }
-
-        @Override
-        public void onAnimationRepeat(Animator animation) {
-
-        }
-    }
-
     private void hideHandle() {
         if (pdfView.getScrollHandle() != null) {
             pdfView.getScrollHandle().hideDelayed();

android-pdf-viewer/src/main/java/com/github/barteksc/pdfviewer/DragPinchManager.java

@@ -133,7 +133,7 @@ public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float d
             pdfView.moveRelativeTo(-distanceX, -distanceY);
         }
         if (!scaling || pdfView.doRenderDuringScale()) {
-          pdfView.loadPageByOffset();
+            pdfView.loadPageByOffset();
         }
         return true;
     }
@@ -152,11 +152,19 @@ public void onLongPress(MotionEvent e) {
     public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
         int xOffset = (int) pdfView.getCurrentXOffset();
         int yOffset = (int) pdfView.getCurrentYOffset();
-        animationManager.startFlingAnimation(xOffset,
-                yOffset, (int) (velocityX),
-                (int) (velocityY),
-                xOffset * (swipeVertical ? 2 : pdfView.getPageCount()), 0,
-                yOffset * (swipeVertical ? pdfView.getPageCount() : 2), 0);
+
+        float minX = pdfView.toCurrentScale(pdfView.getOptimalPageWidth());
+        float minY = pdfView.toCurrentScale(pdfView.getOptimalPageHeight());
+        if (pdfView.isSwipeVertical()) {
+            minX = -(minX - pdfView.getWidth());
+            minY = -(minY * pdfView.getPageCount() - pdfView.getHeight());
+        } else {
+            minX = -(minX * pdfView.getPageCount() - pdfView.getWidth());
+            minY = -(minY - pdfView.getHeight());
+        }
+
+        animationManager.startFlingAnimation(xOffset, yOffset, (int) (velocityX), (int) (velocityY),
+                (int) minX, 0, (int) minY, 0);
 
         return true;
     }

android-pdf-viewer/src/main/java/com/github/barteksc/pdfviewer/PDFView.java

@@ -31,6 +31,7 @@
 import android.os.HandlerThread;
 import android.util.AttributeSet;
 import android.util.Log;
+import android.widget.OverScroller;
 import android.widget.RelativeLayout;
 
 import com.github.barteksc.pdfviewer.listener.OnDrawListener;
@@ -286,7 +287,7 @@ ScrollHandle getScrollHandle() {
      */
     private boolean enableAntialiasing = true;
     private PaintFlagsDrawFilter antialiasFilter =
-            new PaintFlagsDrawFilter(0, Paint.ANTI_ALIAS_FLAG|Paint.FILTER_BITMAP_FLAG);
+            new PaintFlagsDrawFilter(0, Paint.ANTI_ALIAS_FLAG | Paint.FILTER_BITMAP_FLAG);
 
     /**
      * Construct the initial view
@@ -521,6 +522,25 @@ public boolean isRecycled() {
         return recycled;
     }
 
+    /**
+     * Handle fling animation
+     */
+    @Override
+    public void computeScroll() {
+        super.computeScroll();
+
+        OverScroller scroller = animationManager.getScroller();
+        if (scroller.computeScrollOffset()) {
+            moveTo(scroller.getCurrX(), scroller.getCurrY());
+            loadPageByOffset();
+        } else { // fling finished
+            loadPages();
+            if (getScrollHandle() != null) {
+                getScrollHandle().hideDelayed();
+            }
+        }
+    }
+
     @Override
     protected void onDetachedFromWindow() {
         recycle();
@@ -1219,6 +1239,7 @@ public Configurator fromUri(Uri uri) {
 
     /**
      * Use bytearray as the pdf source, documents is not saved
+     *
      * @param bytes
      * @return
      */