Faster ViewPager swiping; Improved logging; Fix: loading huge images;…

… fix memory leak

This is a Backport of PhotoView improvements from  https://github.com/k3b/APhotoManager

* Faster initial loading so swiping through ViewPager is more fluent:
  * initially the view is loaded with low res image. (defined via PhotoView.setImageXxx)
  * on first zoom it is reloaded (defined via PhotoView.setImageReloadFile())
  * see k3b/APhotoManager#10 Fast swiping through images does not work
* Fix: No crash when loading images bigger than 4096x4096 or out of memory
  * HugeImageLoader.java
  * see k3b/APhotoManager#15
* Improved logging
  * possibility to reduce logging: either logg all or info+warn+err or warn+err
    * via LogManager.setLogger() and LogManager.enableDebug()
  * many internal functions get a string parameter `why` so logging shows why a function was called
* fix memory leak

library/build.gradle

@@ -7,8 +7,9 @@ android {
     defaultConfig {
         minSdkVersion 4
         targetSdkVersion 23
-        versionCode 1
-        versionName "1.0"
+		// use values from gradle.properties
+        versionCode=Long.valueOf(VERSION_CODE)
+        versionName=VERSION_NAME
     }
 }
 

library/src/main/java/uk/co/senab/photoview/HugeImageLoader.java

@@ -0,0 +1,101 @@
+package uk.co.senab.photoview;
+
+import android.annotation.TargetApi;
+import android.graphics.Bitmap;
+import android.graphics.BitmapFactory;
+import android.net.Uri;
+import android.opengl.GLES20;
+import android.os.Build;
+
+import java.io.File;
+
+import javax.microedition.khronos.opengles.GL10;
+
+import uk.co.senab.photoview.log.LogManager;
+
+/**
+ * If image is bigger that available memory
+ * load a scaled down version.
+ * see http://developer.android.com/training/displaying-bitmaps/index.html.
+ *
+ * Created by k3b on 14.09.2015.
+ */
+public class HugeImageLoader {
+    public static final String LOG_TAG = "HugeImageLoader";
+
+    // let debug flag be dynamic, but still Proguard can be used to remove from
+    // release builds
+    public static boolean DEBUG = true; //!!! Log.isLoggable(LOG_TAG, Log.DEBUG);
+
+    @TargetApi(Build.VERSION_CODES.FROYO)
+    public static int getMaxTextureSize() {
+        try {
+            int[] max = new int[1];
+            new GLES20().glGetIntegerv(GLES20.GL_MAX_TEXTURE_SIZE, max, 0);
+
+            if (max[0] > 0) {
+                return max[0];
+            }
+        } catch (Exception ex) {
+
+        }
+        return 4096;
+    }
+
+    public static Bitmap loadImage(File file, int maxWidth, int maxHeight) {
+        BitmapFactory.Options options = new BitmapFactory.Options();
+        options.inJustDecodeBounds = true;
+        BitmapFactory.decodeFile(file.getAbsolutePath(), options);
+        // int imageHeight = options.outHeight;
+        // int imageWidth = options.outWidth;
+        // String imageType = options.outMimeType;
+
+        int downscale = calculateInSampleSize(options, maxWidth, maxHeight);
+        options.inSampleSize = downscale;
+
+        if (DEBUG) {
+            Runtime r = Runtime.getRuntime();
+            int width = options.outWidth;
+            int height = options.outHeight;
+            LogManager.getLogger().d(
+                LOG_TAG,
+                "loadImage(" +
+                        "\n\t'" + file +
+                        "', " + width +
+                        "x" + height +
+                        ", max=" + maxWidth +
+                        "x" + maxHeight +
+                        ", size=" + (width*height*4/1024) +
+                        "k, " +
+                        "\n\tmemory(total/free/avail)=(" + r.totalMemory()/1024 + "k,"+ r.freeMemory()/1024+ "k,"+ r.maxMemory()/1024 +
+                        "k) ) " +
+                        "\n\t==> " + width/downscale +
+                        "x" + height/downscale +
+                        ", size=" + (width*height*4/1024/downscale/downscale) +
+                        "k, scale=" + downscale);
+        }
+
+        // Decode bitmap with inSampleSize set
+        options.inJustDecodeBounds = false;
+        return BitmapFactory.decodeFile(file.getAbsolutePath(), options);
+    }
+
+    private static int calculateInSampleSize(
+            BitmapFactory.Options options, int reqWidth, int reqHeight) {
+        // Raw height and width of image
+        int height = options.outHeight;
+        int width = options.outWidth;
+        int inSampleSize = 1;
+
+        // Calculate the largest inSampleSize value that is a power of 2 and keeps both
+        // height and width larger than the requested height and width.
+        while ((height > reqHeight)
+                || (width > reqWidth)) {
+            inSampleSize *= 2;
+            height /= 2;
+            width /= 2;
+        }
+
+        return inSampleSize;
+    }
+}

library/src/main/java/uk/co/senab/photoview/PhotoView.java

@@ -25,12 +25,18 @@
 import android.view.GestureDetector;
 import android.widget.ImageView;
 
+import java.io.File;
+
 import uk.co.senab.photoview.PhotoViewAttacher.OnMatrixChangedListener;
 import uk.co.senab.photoview.PhotoViewAttacher.OnPhotoTapListener;
 import uk.co.senab.photoview.PhotoViewAttacher.OnViewTapListener;
 
 public class PhotoView extends ImageView implements IPhotoView {
 
+    // for debug purposes
+    private static int lastDebugId = 1;
+    private final String mDebugId;
+
     private PhotoViewAttacher mAttacher;
 
     private ScaleType mPendingScaleType;
@@ -45,10 +51,19 @@ public PhotoView(Context context, AttributeSet attr) {
 
     public PhotoView(Context context, AttributeSet attr, int defStyle) {
         super(context, attr, defStyle);
+        // for debug purposes
+        this.mDebugId = "PhotoView#" + (++lastDebugId);
+
         super.setScaleType(ScaleType.MATRIX);
         init();
     }
 
+    // for debug purposes
+    @Override
+    public String toString() {
+        return mDebugId;
+    }
+
     protected void init() {
         if (null == mAttacher || null == mAttacher.getImageView()) {
             mAttacher = new PhotoViewAttacher(this);
@@ -153,23 +168,23 @@ public void setScaleLevels(float minimumScale, float mediumScale, float maximumS
     public void setImageDrawable(Drawable drawable) {
         super.setImageDrawable(drawable);
         if (null != mAttacher) {
-            mAttacher.update();
+            mAttacher.update("setImageDrawable");
         }
     }
 
     @Override
     public void setImageResource(int resId) {
         super.setImageResource(resId);
         if (null != mAttacher) {
-            mAttacher.update();
+            mAttacher.update("setImageResource");
         }
     }
 
     @Override
     public void setImageURI(Uri uri) {
         super.setImageURI(uri);
         if (null != mAttacher) {
-            mAttacher.update();
+            mAttacher.update("setImageURI");
         }
     }
 
@@ -255,6 +270,7 @@ public void setOnSingleFlingListener(PhotoViewAttacher.OnSingleFlingListener onS
     @Override
     protected void onDetachedFromWindow() {
         mAttacher.cleanup();
+        mAttacher = null; // else memory leak
         super.onDetachedFromWindow();
     }
 
@@ -263,4 +279,9 @@ protected void onAttachedToWindow() {
         init();
         super.onAttachedToWindow();
     }
+
+    /** k3b 20150913 #10: Faster initial loading: initially the view is loaded with low res image. on first zoom it is reloaded with this uri */
+    public void setImageReloadFile(File file) {
+        mAttacher.setImageReloadFile(file);
+    }
 }