Allows photoviewer subclasses to modify layouts more freely.

This change allows subclasses of the photoviewer to specify a new
content view layout file with any name, change the name of its root
view, and choose to not include/use the background and/or temporary
image views.

Change-Id: I1227f504311143d3a3ad37f97df1848e912cd3f5

1 files changed, 143 insertions, 65 deletions

diff --git a/src/com/android/ex/photo/PhotoViewController.java b/src/com/android/ex/photo/PhotoViewController.java
index adca9ed..407da45 100644
--- a/src/com/android/ex/photo/PhotoViewController.java
+++ b/src/com/android/ex/photo/PhotoViewController.java
@@ -12,6 +12,8 @@ import android.os.Build;
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.Process;
+import android.support.annotation.IdRes;
+import android.support.annotation.Nullable;
 import android.support.v4.app.Fragment;
 import android.support.v4.app.FragmentManager;
 import android.support.v4.app.LoaderManager;
@@ -144,10 +146,12 @@ public class PhotoViewController implements
     protected View mRootView;
     /** Background image that contains nothing, so it can be alpha faded from
      * transparent to black without affecting any other views. */
+    @Nullable
     protected View mBackground;
     /** The main pager; provides left/right swipe between photos */
     protected PhotoViewPager mViewPager;
     /** The temporary image so that we can quickly scale up the fullscreen thumbnail */
+    @Nullable
     protected ImageView mTemporaryImage;
     /** Adapter to create pager views */
     protected PhotoPagerAdapter mAdapter;
@@ -300,18 +304,18 @@ public class PhotoViewController implements
             mFullScreen = mActionBarHiddenInitially;
         }
 
-        mActivity.setContentView(R.layout.photo_activity_view);
+        mActivity.setContentView(getContentViewId());
 
         // Create the adapter and add the view pager
         mAdapter = createPhotoPagerAdapter(mActivity.getContext(),
                         mActivity.getSupportFragmentManager(), null, mMaxInitialScale);
         final Resources resources = mActivity.getResources();
-        mRootView = findViewById(R.id.photo_activity_root_view);
+        mRootView = findViewById(getRootViewId());
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
             mRootView.setOnSystemUiVisibilityChangeListener(getSystemUiVisibilityChangeListener());
         }
-        mBackground = findViewById(R.id.photo_activity_background);
-        mTemporaryImage = (ImageView) findViewById(R.id.photo_activity_temporary_image);
+        mBackground = getBackground();
+        mTemporaryImage = getTemporaryImage();
         mViewPager = (PhotoViewPager) findViewById(R.id.photo_view_pager);
         mViewPager.setAdapter(mAdapter);
         mViewPager.setOnPageChangeListener(this);
@@ -325,7 +329,9 @@ public class PhotoViewController implements
             mActivity.getSupportLoaderManager().initLoader(LOADER_PHOTO_LIST, null, this);
             // Make the background opaque immediately so that we don't see the activity
             // behind this one.
-            mBackground.setVisibility(View.VISIBLE);
+            if (hasBackground()) {
+                mBackground.setVisibility(View.VISIBLE);
+            }
         } else {
             // Attempt to load the initial image thumbnail. Once we have the
             // image, animate it up. Once the animation is complete, we can kick off
@@ -397,6 +403,58 @@ public class PhotoViewController implements
         return mActivity.findViewById(id);
     }
 
+    /**
+     * Returns the android id of the viewer's root view. Subclasses should override this method if
+     * they provide their own layout.
+     */
+    @IdRes
+    protected int getRootViewId() {
+      return R.id.photo_activity_root_view;
+    }
+
+    /**
+     * Returns the android layout id of the root layout that should be inflated for the viewer.
+     * Subclasses should override this method if they provide their own layout.
+     */
+    @IdRes
+    protected int getContentViewId() {
+        return R.layout.photo_activity_view;
+    }
+
+    /**
+     * Returns the android view for the viewer's background view, if it has one. Subclasses should
+     * override this if they have a different (or no) background view.
+     */
+    @Nullable
+    protected View getBackground() {
+        return findViewById(R.id.photo_activity_background);
+    }
+
+    /**
+     * Returns whether or not the view has a background object. Subclasses should override this if
+     * they do not contain a background object.
+     */
+    protected boolean hasBackground() {
+        return mBackground != null;
+    }
+
+    /**
+     * Returns the android view for the viewer's temporary image, if it has one. Subclasses should
+     * override this if they have a different (or no) temporary image view.
+     */
+    @Nullable
+    protected ImageView getTemporaryImage() {
+        return (ImageView) findViewById(R.id.photo_activity_temporary_image);
+    }
+
+    /**
+     * Returns whether or not the view has a temporary image view. Subclasses should override this
+     * if they do not use a temporary image.
+     */
+    protected boolean hasTemporaryImage() {
+        return mTemporaryImage != null;
+    }
+
     public void onStart() {}
 
     public void onResume() {
@@ -877,11 +935,13 @@ public class PhotoViewController implements
 
     @Override
     public void onFragmentPhotoLoadComplete(PhotoViewFragment fragment, boolean success) {
-        if (mTemporaryImage.getVisibility() != View.GONE &&
+        if (hasTemporaryImage() && mTemporaryImage.getVisibility() != View.GONE &&
                 TextUtils.equals(fragment.getPhotoUri(), mCurrentPhotoUri)) {
             if (success) {
                 // The fragment for the current image is now ready for display.
-                mTemporaryImage.setVisibility(View.GONE);
+                if (hasTemporaryImage()) {
+                    mTemporaryImage.setVisibility(View.GONE);
+                }
                 mViewPager.setVisibility(View.VISIBLE);
             } else {
                 // This means that we are unable to load the fragment's photo.
@@ -889,7 +949,9 @@ public class PhotoViewController implements
                 // we display the viewPager, the fragment itself can decide how to
                 // display the failure of its own image.
                 Log.w(TAG, "Failed to load fragment image");
-                mTemporaryImage.setVisibility(View.GONE);
+                if (hasTemporaryImage()) {
+                    mTemporaryImage.setVisibility(View.GONE);
+                }
                 mViewPager.setVisibility(View.VISIBLE);
             }
             mActivity.getSupportLoaderManager().destroyLoader(
@@ -929,7 +991,9 @@ public class PhotoViewController implements
         // FLAG: Need to handle the aspect ratio of the bitmap.  If it's a portrait
         // bitmap, then we need to position the view higher so that the middle
         // pixels line up.
-        mTemporaryImage.setVisibility(View.VISIBLE);
+        if (hasTemporaryImage()) {
+            mTemporaryImage.setVisibility(View.VISIBLE);
+        }
         // We need to take a full screen image, and scale/translate it so that
         // it appears at exactly the same location onscreen as it is in the
         // prior activity.
@@ -946,60 +1010,68 @@ public class PhotoViewController implements
 
         final int version = android.os.Build.VERSION.SDK_INT;
         if (version >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
-            mBackground.setAlpha(0f);
-            mBackground.animate().alpha(1f).setDuration(ENTER_ANIMATION_DURATION_MS).start();
-            mBackground.setVisibility(View.VISIBLE);
+            if (hasBackground()) {
+                mBackground.setAlpha(0f);
+                mBackground.animate().alpha(1f).setDuration(ENTER_ANIMATION_DURATION_MS).start();
+                mBackground.setVisibility(View.VISIBLE);
+            }
 
-            mTemporaryImage.setScaleX(scale);
-            mTemporaryImage.setScaleY(scale);
-            mTemporaryImage.setTranslationX(translateX);
-            mTemporaryImage.setTranslationY(translateY);
+            if (hasTemporaryImage()) {
+                mTemporaryImage.setScaleX(scale);
+                mTemporaryImage.setScaleY(scale);
+                mTemporaryImage.setTranslationX(translateX);
+                mTemporaryImage.setTranslationY(translateY);
 
-            Runnable endRunnable = new Runnable() {
-                @Override
-                public void run() {
-                    PhotoViewController.this.onEnterAnimationComplete();
+                Runnable endRunnable = new Runnable() {
+                    @Override
+                    public void run() {
+                        PhotoViewController.this.onEnterAnimationComplete();
+                    }
+                };
+                ViewPropertyAnimator animator = mTemporaryImage.animate().scaleX(1f).scaleY(1f)
+                    .translationX(0).translationY(0).setDuration(ENTER_ANIMATION_DURATION_MS);
+                if (version >= Build.VERSION_CODES.JELLY_BEAN) {
+                    animator.withEndAction(endRunnable);
+                } else {
+                    mHandler.postDelayed(endRunnable, ENTER_ANIMATION_DURATION_MS);
                 }
-            };
-            ViewPropertyAnimator animator = mTemporaryImage.animate().scaleX(1f).scaleY(1f)
-                .translationX(0).translationY(0).setDuration(ENTER_ANIMATION_DURATION_MS);
-            if (version >= Build.VERSION_CODES.JELLY_BEAN) {
-                animator.withEndAction(endRunnable);
-            } else {
-                mHandler.postDelayed(endRunnable, ENTER_ANIMATION_DURATION_MS);
+                animator.start();
             }
-            animator.start();
         } else {
-            final Animation alphaAnimation = new AlphaAnimation(0f, 1f);
-            alphaAnimation.setDuration(ENTER_ANIMATION_DURATION_MS);
-            mBackground.startAnimation(alphaAnimation);
-            mBackground.setVisibility(View.VISIBLE);
-
-            final Animation translateAnimation = new TranslateAnimation(translateX,
-                    translateY, 0, 0);
-            translateAnimation.setDuration(ENTER_ANIMATION_DURATION_MS);
-            Animation scaleAnimation = new ScaleAnimation(scale, scale, 0, 0);
-            scaleAnimation.setDuration(ENTER_ANIMATION_DURATION_MS);
-
-            AnimationSet animationSet = new AnimationSet(true);
-            animationSet.addAnimation(translateAnimation);
-            animationSet.addAnimation(scaleAnimation);
-            AnimationListener listener = new AnimationListener() {
-                @Override
-                public void onAnimationEnd(Animation arg0) {
-                    PhotoViewController.this.onEnterAnimationComplete();
-                }
+            if (hasBackground()) {
+                final Animation alphaAnimation = new AlphaAnimation(0f, 1f);
+                alphaAnimation.setDuration(ENTER_ANIMATION_DURATION_MS);
+                mBackground.startAnimation(alphaAnimation);
+                mBackground.setVisibility(View.VISIBLE);
+            }
 
-                @Override
-                public void onAnimationRepeat(Animation arg0) {
-                }
+            if (hasTemporaryImage()) {
+                final Animation translateAnimation = new TranslateAnimation(translateX,
+                        translateY, 0, 0);
+                translateAnimation.setDuration(ENTER_ANIMATION_DURATION_MS);
+                Animation scaleAnimation = new ScaleAnimation(scale, scale, 0, 0);
+                scaleAnimation.setDuration(ENTER_ANIMATION_DURATION_MS);
+
+                AnimationSet animationSet = new AnimationSet(true);
+                animationSet.addAnimation(translateAnimation);
+                animationSet.addAnimation(scaleAnimation);
+                AnimationListener listener = new AnimationListener() {
+                    @Override
+                    public void onAnimationEnd(Animation arg0) {
+                        PhotoViewController.this.onEnterAnimationComplete();
+                    }
 
-                @Override
-                public void onAnimationStart(Animation arg0) {
-                }
-            };
-            animationSet.setAnimationListener(listener);
-            mTemporaryImage.startAnimation(animationSet);
+                    @Override
+                    public void onAnimationRepeat(Animation arg0) {
+                    }
+
+                    @Override
+                    public void onAnimationStart(Animation arg0) {
+                    }
+                };
+                animationSet.setAnimationListener(listener);
+                mTemporaryImage.startAnimation(animationSet);
+            }
         }
     }
 
@@ -1027,8 +1099,10 @@ public class PhotoViewController implements
                 totalHeight, scale);
         final int version = android.os.Build.VERSION.SDK_INT;
         if (version >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
-            mBackground.animate().alpha(0f).setDuration(EXIT_ANIMATION_DURATION_MS).start();
-            mBackground.setVisibility(View.VISIBLE);
+            if (hasBackground()) {
+                mBackground.animate().alpha(0f).setDuration(EXIT_ANIMATION_DURATION_MS).start();
+                mBackground.setVisibility(View.VISIBLE);
+            }
 
             Runnable endRunnable = new Runnable() {
                 @Override
@@ -1040,7 +1114,7 @@ public class PhotoViewController implements
             // not yet loaded the fullres image, so we need to animate
             // the temporary image out.
             ViewPropertyAnimator animator = null;
-            if (mTemporaryImage.getVisibility() == View.VISIBLE) {
+            if (hasTemporaryImage() && mTemporaryImage.getVisibility() == View.VISIBLE) {
                 animator = mTemporaryImage.animate().scaleX(scale).scaleY(scale)
                     .translationX(translateX).translationY(translateY)
                     .setDuration(EXIT_ANIMATION_DURATION_MS);
@@ -1061,10 +1135,12 @@ public class PhotoViewController implements
             }
             animator.start();
         } else {
-            final Animation alphaAnimation = new AlphaAnimation(1f, 0f);
-            alphaAnimation.setDuration(EXIT_ANIMATION_DURATION_MS);
-            mBackground.startAnimation(alphaAnimation);
-            mBackground.setVisibility(View.VISIBLE);
+            if (hasBackground()) {
+                final Animation alphaAnimation = new AlphaAnimation(1f, 0f);
+                alphaAnimation.setDuration(EXIT_ANIMATION_DURATION_MS);
+                mBackground.startAnimation(alphaAnimation);
+                mBackground.setVisibility(View.VISIBLE);
+            }
 
             final Animation scaleAnimation = new ScaleAnimation(1f, 1f, scale, scale);
             scaleAnimation.setDuration(EXIT_ANIMATION_DURATION_MS);
@@ -1086,7 +1162,7 @@ public class PhotoViewController implements
             // If the temporary image is still visible it means that we have
             // not yet loaded the fullres image, so we need to animate
             // the temporary image out.
-            if (mTemporaryImage.getVisibility() == View.VISIBLE) {
+            if (hasTemporaryImage() && mTemporaryImage.getVisibility() == View.VISIBLE) {
                 mTemporaryImage.startAnimation(scaleAnimation);
             } else {
                 mViewPager.startAnimation(scaleAnimation);
@@ -1124,7 +1200,9 @@ public class PhotoViewController implements
             // Forget this, we've already run the animation.
             return;
         }
-        mTemporaryImage.setImageDrawable(drawable);
+        if (hasTemporaryImage()) {
+            mTemporaryImage.setImageDrawable(drawable);
+        }
         if (drawable != null) {
             // We have not yet run the enter animation. Start it now.
             int totalWidth = mRootView.getMeasuredWidth();