Make the back button behaviour configurable. The default should remain

identical to the most recent behaviour. As an option, the user can force
back to always go "up" a level like Jesse likes

res/values/strings.xml

@@ -724,7 +724,11 @@ Welcome to K-9 Mail setup.  K-9 is an open source mail client for Android origin
     <string name="animations_summary">Use gaudy visual effects</string>
     <string name="gestures_title">Gestures</string>
     <string name="gestures_summary">Accept gesture control</string>
-    
+
+    <string name="manage_back_title">Manage "Back" button</string>
+    <string name="manage_back_summary">Make "Back" always go up a level</string>
+
+
     <string name="measure_accounts_title">Show account size</string>
     <string name="measure_accounts_summary">Turn off for faster display</string>
     

res/xml/global_preferences.xml

@@ -48,6 +48,12 @@
             android:title="@string/gestures_title"
             android:summary="@string/gestures_summary" />
 
+        <CheckBoxPreference
+            android:key="manage_back"
+            android:title="@string/manage_back_title"
+            android:summary="@string/manage_back_summary" />
+
+
     </PreferenceCategory>
 
     <PreferenceCategory android:title="@string/accountlist_preferences" android:key="accountlist_preferences">

src/com/fsck/k9/K9.java

@@ -79,6 +79,7 @@ public class K9 extends Application
     private static boolean mMessageListCheckboxes = false;
     private static boolean mMessageListTouchable = false;
     private static boolean mGesturesEnabled = true;
+    private static boolean mManageBack = false;
     private static boolean mMeasureAccounts = true;
     private static boolean mCountSearchMessages = true;
 
@@ -297,6 +298,7 @@ public class K9 extends Application
         editor.putString("backgroundOperations", K9.backgroundOps.toString());
         editor.putBoolean("animations", mAnimations);
         editor.putBoolean("gesturesEnabled", mGesturesEnabled);
+        editor.putBoolean("manageBack", mManageBack);
         editor.putBoolean("measureAccounts", mMeasureAccounts);
         editor.putBoolean("countSearchMessages", mCountSearchMessages);
         editor.putBoolean("messageListStars",mMessageListStars);
@@ -322,6 +324,7 @@ public class K9 extends Application
         DEBUG_SENSITIVE = sprefs.getBoolean("enableSensitiveLogging", false);
         mAnimations = sprefs.getBoolean("animations", true);
         mGesturesEnabled = sprefs.getBoolean("gesturesEnabled", true);
+        mManageBack = sprefs.getBoolean("manageBack", false);
         mMeasureAccounts = sprefs.getBoolean("measureAccounts", true);
         mCountSearchMessages = sprefs.getBoolean("countSearchMessages", true);
         mMessageListStars = sprefs.getBoolean("messageListStars",true);
@@ -451,6 +454,17 @@ public class K9 extends Application
         mGesturesEnabled = gestures;
     }
 
+
+    public static boolean manageBack()
+    {
+        return mManageBack;
+    }
+
+    public static void setManageBack(boolean manageBack)
+    {
+        mManageBack = manageBack;
+    }
+
     public static boolean isAnimations()
     {
         return mAnimations;

src/com/fsck/k9/activity/FolderList.java

@@ -355,9 +355,36 @@ public class FolderList extends K9ListActivity
     }
 
 
+    public void onBackPressed()
+    {
+        // This will be called either automatically for you on 2.0
+        // or later, or by the code above on earlier versions of the
+        // platform.
+        if (K9.manageBack() ) 
+        {
+        onAccounts();
+        }
+    }
+
     @Override public boolean onKeyDown(int keyCode, KeyEvent event)
     {
         //Shortcuts that work no matter what is selected
+
+        if (
+            // TODO - when we move to android 2.0, uncomment this.
+            // android.os.Build.VERSION.SDK_INT < android.os.Build.VERSION_CODES.ECLAIR &&
+
+            keyCode == KeyEvent.KEYCODE_BACK
+            && event.getRepeatCount() == 0
+            && K9.manageBack() )
+        {
+            // Take care of calling this method on earlier versions of
+            // the platform where it doesn't exist.
+            onBackPressed();
+            return true;
+        }
+
+
         switch (keyCode)
         {
             case KeyEvent.KEYCODE_Q:
@@ -533,6 +560,7 @@ public class FolderList extends K9ListActivity
     private void onOpenFolder(String folder)
     {
         MessageList.actionHandleFolder(this, mAccount, folder);
+        finish();
     }
 
     private void onCompact(Account account)

src/com/fsck/k9/activity/MessageList.java

@@ -575,9 +575,35 @@ public class MessageList
     }
 
 
+    public void onBackPressed()
+    {
+        // This will be called either automatically for you on 2.0
+        // or later, or by the code above on earlier versions of the
+        // platform.
+        if (K9.manageBack()) 
+        {
+            onShowFolderList();
+        } else {
+            finish();
+        }
+    }
+
+
     @Override
     public boolean onKeyDown(int keyCode, KeyEvent event)
     {
+        if (
+            // XXX TODO - when we go to android 2.0, uncomment this
+            // android.os.Build.VERSION.SDK_INT < android.os.Build.VERSION_CODES.ECLAIR &&
+            keyCode == KeyEvent.KEYCODE_BACK
+            && event.getRepeatCount() == 0 
+            )
+        {
+            // Take care of calling this method on earlier versions of
+            // the platform where it doesn't exist.
+            onBackPressed();
+            return true;
+        }
         //Shortcuts that work no matter what is selected
 
         switch (keyCode)

src/com/fsck/k9/activity/setup/Prefs.java

@@ -28,6 +28,7 @@ public class Prefs extends K9PreferenceActivity
 
     private static final String PREFERENCE_ANIMATIONS = "animations";
     private static final String PREFERENCE_GESTURES = "gestures";
+    private static final String PREFERENCE_MANAGE_BACK = "manage_back";
     private static final String PREFERENCE_MESSAGELIST_STARS = "messagelist_stars";
     private static final String PREFERENCE_MESSAGELIST_CHECKBOXES = "messagelist_checkboxes";
     private static final String PREFERENCE_MESSAGELIST_TOUCHABLE = "messagelist_touchable";
@@ -41,6 +42,7 @@ public class Prefs extends K9PreferenceActivity
     private CheckBoxPreference mDebugLogging;
     private CheckBoxPreference mSensitiveLogging;
     private CheckBoxPreference mGestures;
+    private CheckBoxPreference mManageBack;
     private CheckBoxPreference mAnimations;
     private CheckBoxPreference mStars;
     private CheckBoxPreference mCheckboxes;
@@ -146,6 +148,10 @@ public class Prefs extends K9PreferenceActivity
         mGestures = (CheckBoxPreference)findPreference(PREFERENCE_GESTURES);
         mGestures.setChecked(K9.gesturesEnabled());
 
+        mManageBack = (CheckBoxPreference)findPreference(PREFERENCE_MANAGE_BACK);
+        mManageBack.setChecked(K9.manageBack());
+
+
         mStars = (CheckBoxPreference)findPreference(PREFERENCE_MESSAGELIST_STARS);
         mStars.setChecked(K9.messageListStars());
 
@@ -181,6 +187,7 @@ public class Prefs extends K9PreferenceActivity
 
         K9.setAnimations(mAnimations.isChecked());
         K9.setGesturesEnabled(mGestures.isChecked());
+        K9.setManageBack(mManageBack.isChecked());
         K9.setMessageListStars(mStars.isChecked());
         K9.setMessageListCheckboxes(mCheckboxes.isChecked());