Remember switched conversations across screen orientation changes

As of now, the activity does not remember whether a conversation is
switched across configuration changes (such as screen rotations).  Fix
this by adding onSaveInstanceState() and onRestoreInstanceState()
callbacks in the activity to pass this information to the new instance.

To make the implementation of this simpler, all code to configure the
MessageListView, which was duplicated in several places in the codebase,
has been moved to the MessageListView's constructor.

While we're at it, make the padding setting independent of screen
density instead of specifying in fixed pixels (equivalent to specifying
the value in dp instead of px), and increase the padding for switched
views.  This ensures that message text isn't obscured by the gradient at
the edges of the ConversationGallery, which started happening when we
began caching MessageListViews in the DeckAdapter.

application/src/org/yaaic/activity/ConversationActivity.java

@@ -273,6 +273,33 @@ public class ConversationActivity extends Activity implements ServiceConnection,
         unregisterReceiver(serverReceiver);
     }
 
+    /**
+     * On save instance state (e.g. before a configuration change)
+     */
+    @Override
+    protected void onSaveInstanceState(Bundle outState)
+    {
+        super.onSaveInstanceState(outState);
+
+        if (deckAdapter.isSwitched()) {
+            outState.putBoolean("isSwitched", deckAdapter.isSwitched());
+            outState.putString("switchedName", deckAdapter.getSwitchedName());
+        }
+    }
+
+    /**
+     * On restore instance state (e.g. after a configuration change)
+     */
+    @Override
+    protected void onRestoreInstanceState(Bundle inState)
+    {
+        super.onRestoreInstanceState(inState);
+
+        if (inState.getBoolean("isSwitched")) {
+            deckAdapter.setSwitched(inState.getString("switchedName"), null);
+        }
+    }
+
     /**
      * On service connected
      */
@@ -528,9 +555,7 @@ public class ConversationActivity extends Activity implements ServiceConnection,
         if (keyCode == KeyEvent.KEYCODE_BACK && event.getRepeatCount() == 0) {
             if (deckAdapter.isSwitched()) {
                 MessageListView canvas = (MessageListView) deckAdapter.getView(deckAdapter.getPositionByName(deckAdapter.getSwitchedName()), null, switcher);
-                canvas.setLayoutParams(new Gallery.LayoutParams(switcher.getWidth()*85/100, switcher.getHeight()));
+                canvas.setSwitched(false);
-                canvas.setTranscriptMode(MessageListView.TRANSCRIPT_MODE_ALWAYS_SCROLL);
-                canvas.setDelegateTouchEvents(true);
                 deckAdapter.setSwitched(null, null);
                 return true;
             }

application/src/org/yaaic/adapter/DeckAdapter.java

@@ -225,7 +225,7 @@ public class DeckAdapter extends BaseAdapter
      */
     public boolean isSwitched()
     {
-        return currentView != null;
+        return currentChannel != null;
     }
 
     /**
@@ -272,20 +272,12 @@ public class DeckAdapter extends BaseAdapter
         }
 
         list.setAdapter(adapter);
+        list.setSelection(adapter.getCount() - 1); // scroll to bottom
 
-        list.setDivider(null);
+        if (convInfo.conv.getName().equals(currentChannel)) {
-        list.setLayoutParams(new Gallery.LayoutParams(
+            list.setSwitched(true);
-            parent.getWidth()*85/100,
+            currentView = list;
-            parent.getHeight()
+        }
-        ));
-
-        list.setBackgroundResource(R.layout.rounded);
-        list.setCacheColorHint(0xee000000);
-        list.setPadding(5, 5, 5, 5);
-        list.setVerticalFadingEdgeEnabled(false);
-        list.setScrollBarStyle(ListView.SCROLLBARS_OUTSIDE_INSET);
-        list.setTranscriptMode(ListView.TRANSCRIPT_MODE_ALWAYS_SCROLL);
-        list.setSelection(list.getAdapter().getCount() - 1); // scroll to bottom
 
         return list;
     }

application/src/org/yaaic/listener/ConversationClickListener.java

@@ -62,10 +62,7 @@ public class ConversationClickListener implements OnItemClickListener
         Conversation conversation = adapter.getItem(position);
 
         MessageListView canvas = (MessageListView) adapter.getView(position, null, switcher);
-        canvas.setTranscriptMode(ListView.TRANSCRIPT_MODE_NORMAL);
+        canvas.setSwitched(true);
-        canvas.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));
-        canvas.setDelegateTouchEvents(false); // Do not delegate
-
         adapter.setSwitched(conversation.getName(), canvas);
     }
 }

application/src/org/yaaic/view/MessageListView.java

@@ -20,6 +20,7 @@ along with Yaaic.  If not, see <http://www.gnu.org/licenses/>.
  */
 package org.yaaic.view;
 
+import org.yaaic.R;
 import org.yaaic.adapter.MessageListAdapter;
 import org.yaaic.listener.MessageClickListener;
 
@@ -37,10 +38,12 @@ import android.widget.ListView;
  */
 public class MessageListView extends ListView
 {
-    private boolean delegate = true;
+    private boolean switched = false;
     private final View parent;
     private int parentWidth;
     private int parentHeight;
+    private int padding;
+    private int paddingWide;
 
     /**
      * Create a new MessageListView
@@ -52,20 +55,28 @@ public class MessageListView extends ListView
         super(context);
 
         this.parent = parent;
-        this.setOnItemClickListener(MessageClickListener.getInstance());
+        setOnItemClickListener(MessageClickListener.getInstance());
 
         parentWidth = parent.getWidth();
         parentHeight = parent.getHeight();
-    }
 
-    /**
+        setDivider(null);
-     * Should all touch events delegated?
+        setLayoutParams(new Gallery.LayoutParams(
-     * 
+            parentWidth*85/100,
-     * @param delegate If true all touch events will be delegated, otherwise the listview will handle them
+            parentHeight
-     */
+        ));
-    public void setDelegateTouchEvents(boolean delegate)
+
-    {
+        setBackgroundResource(R.layout.rounded);
-        this.delegate = delegate;
+        setCacheColorHint(0xee000000);
+        setVerticalFadingEdgeEnabled(false);
+        setScrollBarStyle(SCROLLBARS_OUTSIDE_INSET);
+        setTranscriptMode(TRANSCRIPT_MODE_ALWAYS_SCROLL);
+
+        // Scale padding by screen density
+        float density = context.getResources().getDisplayMetrics().density;
+        padding = (int)(5 * density);
+        paddingWide = (int)(12 * density);
+        setPadding(padding, padding, padding, padding);
     }
 
     /**
@@ -74,7 +85,7 @@ public class MessageListView extends ListView
     @Override
     public boolean onTouchEvent(MotionEvent event)
     {
-        if (delegate) {
+        if (!switched) {
             // We delegate the touch events to the underlying view
             return false;
         } else {
@@ -88,17 +99,19 @@ public class MessageListView extends ListView
     @Override
     protected void onDraw(Canvas canvas)
     {
-        if (delegate && (parent.getWidth() != parentWidth || parent.getHeight() != parentHeight)) {
+        if (parent.getWidth() != parentWidth || parent.getHeight() != parentHeight) {
             // parent size changed, resizing this child too
 
             parentWidth = parent.getWidth();
             parentHeight = parent.getHeight();
 
-            this.setLayoutParams(new Gallery.LayoutParams(
+            if (!switched) {
+                setLayoutParams(new Gallery.LayoutParams(
                     parentWidth*85/100,
                     parentHeight
                 ));
             }
+        }
 
         super.onDraw(canvas);
     }
@@ -114,4 +127,23 @@ public class MessageListView extends ListView
     {
         return (MessageListAdapter) super.getAdapter();
     }
+
+    /**
+     * Set whether this conversation is switched (taking up all of deck's space
+     * and handling touch events itself)
+     */
+    public void setSwitched(boolean switched)
+    {
+        this.switched = switched;
+
+        if (switched) {
+            setLayoutParams(new Gallery.LayoutParams(Gallery.LayoutParams.FILL_PARENT, Gallery.LayoutParams.FILL_PARENT));
+            setTranscriptMode(TRANSCRIPT_MODE_NORMAL);
+            setPadding(paddingWide, padding, paddingWide, padding);
+        } else {
+            setLayoutParams(new Gallery.LayoutParams(parentWidth*85/100, parentHeight));
+            setTranscriptMode(TRANSCRIPT_MODE_ALWAYS_SCROLL);
+            setPadding(padding, padding, padding, padding);
+        }
+    }
 }