Swap works on 2.3 devices.

* Cleaned up text alignment styles for API < 17.

API v17 has a textAlignment style, wherease previous verisons rely on
the "gravity" property. This change includes gravity="center" where there
was previously only textAlignment="center".

 * Fragments get added properly on 2.3 device.

For some reason, when adding the fragment to android.R.id.content, it
wouldn't work on my 2.3 device. This change includes a (almost) empty
activity layout with a single FrameLayout. The fragments are added to
this rather than "content", and it works better. It is not perfect - it
still adds the fargments behind the action bar, and so the action bar
appears blue. But at least they are there :)

 * Added translatable strings where constants were used before.

Not related to v2.3 support, but stil important for a stable release,
that is fully translated.

F-Droid/res/layout/swap_activity.xml

@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="utf-8"?>
+<RelativeLayout
+        xmlns:android="http://schemas.android.com/apk/res/android"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent">
+
+    <FrameLayout
+            android:id="@+id/fragment_container"
+            android:layout_width="fill_parent"
+            android:layout_height="fill_parent">
+
+    </FrameLayout>
+
+</RelativeLayout>

F-Droid/res/layout/swap_blank.xml

@@ -8,14 +8,14 @@
 
     <TextView
             android:id="@+id/text_description"
-            android:text="Your mobile device becomes an app store with Swap!"
+            android:text="@string/swap_introduction"
             style="@style/SwapTheme.StartSwap.MainText"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content" />
 
     <Button
             android:id="@+id/button_start_swap"
-            android:text="START A SWAP"
+            android:text="@string/swap_start"
             style="@style/SwapTheme.StartSwap.StartButton"
             android:layout_width="match_parent"
             android:layout_below="@+id/text_description"

F-Droid/res/values/strings.xml

@@ -307,4 +307,6 @@
     <string name="open_qr_code_scanner">Open QR Code Scanner</string>
     <string name="swap_welcome">Welcome to F-Droid!</string>
     <string name="swap_confirm_connect">Do you want to get apps from %1$s now?</string>
+    <string name="swap_introduction">Your mobile device becomes an app store with Swap!</string>
+    <string name="swap_start">START A SWAP</string>
 </resources>

F-Droid/res/values/styles.xml

@@ -12,14 +12,14 @@
         <!-- backward-compatibility theme options go here -->
     </style>
 
-	<color name="black">#FF000000</color>
+    <color name="black">#FF000000</color>
-	<color name="white">#FFFFFFFF</color>
+    <color name="white">#FFFFFFFF</color>
-	<color name="red">#FFFF0000</color>
+    <color name="red">#FFFF0000</color>
 
-	<style name="AboutDialogLight" parent="@android:style/Theme.Dialog">
+    <style name="AboutDialogLight" parent="@android:style/Theme.Dialog">
-		<item name="@android:windowBackground">@color/black</item>
+        <item name="@android:windowBackground">@color/black</item>
-		<item name="@android:textColor">@color/white</item>
+        <item name="@android:textColor">@color/white</item>
-	</style>
+    </style>
 
     <style name="AppThemeDark" parent="AppBaseThemeDark">
         <!-- customizations that are not API-level specific go here. -->
@@ -65,6 +65,7 @@
 
     <style name="SwapTheme.AppList.SwapSuccess">
         <item name="android:textAlignment">center</item>
+        <item name="android:gravity">center</item>
         <item name="android:textSize">25.7sp</item> <!-- 46px * 96dpi / 160dpi -->
         <item name="android:paddingTop">28dp</item> <!-- 50px * 96dpi / 160dpi -->
         <item name="android:paddingBottom">20.1dp</item> <!-- 36px * 96dpi / 160dpi -->
@@ -73,6 +74,7 @@
 
     <style name="SwapTheme.AppList.SwapSuccessDetails">
         <item name="android:textAlignment">center</item>
+        <item name="android:gravity">center</item>
         <item name="android:textSize">20.1sp</item> <!-- 36px * 96dpi / 160dpi -->
         <item name="android:paddingTop">20.1dp</item> <!-- 36px * 96dpi / 160dpi -->
         <item name="android:paddingBottom">20.1dp</item> <!-- 36px * 96dpi / 160dpi -->
@@ -81,6 +83,7 @@
 
     <style name="SwapTheme.StartSwap.MainText">
         <item name="android:textAlignment">center</item>
+        <item name="android:gravity">center</item>
         <item name="android:textSize">20.1sp</item> <!-- 36px * 96dpi / 160dpi -->
         <item name="android:paddingLeft">28dp</item> <!-- 50px * 96dpi / 160dpi -->
         <item name="android:paddingRight">28dp</item> <!-- 50px * 96dpi / 160dpi -->
@@ -90,6 +93,7 @@
 
     <style name="SwapTheme.Wizard.Text">
         <item name="android:textAlignment">center</item>
+        <item name="android:gravity">center</item>
         <item name="android:textColor">#fff</item>
         <item name="android:textColorPrimary">#fff</item>
         <item name="android:textColorSecondary">#fff</item>

F-Droid/src/org/fdroid/fdroid/views/swap/SwapActivity.java

@@ -80,6 +80,8 @@ public class SwapActivity extends ActionBarActivity implements SwapProcessManage
 
         if (savedInstanceState == null) {
 
+            setContentView(R.layout.swap_activity);
+
             showFragment(new StartSwapFragment(), STATE_START_SWAP);
 
             if (FDroidApp.isLocalRepoServiceRunning()) {
@@ -133,7 +135,7 @@ public class SwapActivity extends ActionBarActivity implements SwapProcessManage
     private void showFragment(Fragment fragment, String name) {
         getSupportFragmentManager()
                 .beginTransaction()
-                .replace(android.R.id.content, fragment, name)
+                .replace(R.id.fragment_container, fragment, name)
                 .addToBackStack(name)
                 .commit();
     }