commit 0c24a5514c1ff143a223720a090b19a86a75945f
author Adam Powell <adamp@google.com> Wed Nov 03 16:44:11 2010 -0700
committer Adam Powell <adamp@google.com> Wed Nov 03 19:24:19 2010 -0700
tree 1ecacc7e69a9eba51e1956c597de1427a571b79d
parent 079e23575024e103358c982152afb7a720ae1a8a

Fix bug 3156280 - Fix several issues with tab navigation in action bars.

Add the ability to restrict a FragmentTransaction's ability to be
added to the back stack. (It doesn't make sense for tabs or other
scenarios to allow this.)

Change-Id: I8fa2edb5f35c365e2483010ad13eb9993f5e6570

core/java/com/android/internal/app/ActionBarImpl.java

diff --git a/core/java/com/android/internal/app/ActionBarImpl.java b/core/java/com/android/internal/app/ActionBarImpl.java
index 1d612e2..7cf369f 100644
--- a/core/java/com/android/internal/app/ActionBarImpl.java
+++ b/core/java/com/android/internal/app/ActionBarImpl.java
@@ -65,12 +65,15 @@
     private ArrayList<TabImpl> mTabs = new ArrayList<TabImpl>();
 
     private TabImpl mSelectedTab;
+    private int mSavedTabPosition = INVALID_POSITION;
     
     private ActionMode mActionMode;
     
     private static final int CONTEXT_DISPLAY_NORMAL = 0;
     private static final int CONTEXT_DISPLAY_SPLIT = 1;
     
+    private static final int INVALID_POSITION = -1;
+
     private int mContextDisplayMode;
 
     private boolean mClosingContext;
@@ -183,6 +186,8 @@
             selectTab(null);
         }
         mTabs.clear();
+        mActionView.removeAllTabs();
+        mSavedTabPosition = INVALID_POSITION;
     }
 
     public void setTitle(CharSequence title) {
@@ -310,6 +315,8 @@
 
     @Override
     public void removeTabAt(int position) {
+        int selectedTabPosition = mSelectedTab != null
+                ? mSelectedTab.getPosition() : mSavedTabPosition;
         mActionView.removeTabAt(position);
         mTabs.remove(position);
 
@@ -318,7 +325,9 @@
             mTabs.get(i).setPosition(i);
         }
 
-        selectTab(mTabs.isEmpty() ? null : mTabs.get(Math.max(0, position - 1)));
+        if (selectedTabPosition == position) {
+            selectTab(mTabs.isEmpty() ? null : mTabs.get(Math.max(0, position - 1)));
+        }
     }
 
     @Override
@@ -333,7 +342,13 @@
 
     @Override
     public void selectTab(Tab tab) {
-        final FragmentTransaction trans = mActivity.getFragmentManager().openTransaction();
+        if (getNavigationMode() != NAVIGATION_MODE_TABS) {
+            mSavedTabPosition = tab != null ? tab.getPosition() : INVALID_POSITION;
+            return;
+        }
+
+        final FragmentTransaction trans = mActivity.getFragmentManager().openTransaction()
+                .disallowAddToBackStack();
 
         if (mSelectedTab == tab) {
             if (mSelectedTab != null) {
@@ -623,12 +638,52 @@
     }
 
     @Override
+    public int getTabCount() {
+        return mTabs.size();
+    }
+
+    @Override
     public void setNavigationMode(int mode) {
+        final int oldMode = mActionView.getNavigationMode();
+        switch (oldMode) {
+            case NAVIGATION_MODE_TABS:
+                mSavedTabPosition = getSelectedNavigationIndex();
+                selectTab(null);
+                break;
+        }
         mActionView.setNavigationMode(mode);
+        switch (mode) {
+            case NAVIGATION_MODE_TABS:
+                if (mSavedTabPosition != INVALID_POSITION) {
+                    setSelectedNavigationItem(mSavedTabPosition);
+                    mSavedTabPosition = INVALID_POSITION;
+                }
+                break;
+        }
     }
 
     @Override
     public Tab getTabAt(int index) {
         return mTabs.get(index);
     }
+
+    /**
+     * This fragment is added when we're keeping a back stack in a tab switch
+     * transaction. We use it to change the selected tab in the action bar view
+     * when we back out.
+     */
+    private class SwitchSelectedTabViewFragment extends Fragment {
+        private int mSelectedTabIndex;
+
+        public SwitchSelectedTabViewFragment(int oldSelectedTab) {
+            mSelectedTabIndex = oldSelectedTab;
+        }
+
+        @Override
+        public void onDetach() {
+            if (mSelectedTabIndex >= 0 && mSelectedTabIndex < getTabCount()) {
+                mActionView.setTabSelected(mSelectedTabIndex);
+            }
+        }
+    }
 }