Add docs on regeneration background text image

Also add a missing string in the recovery_l10n APP.

Bug: 30415666
Change-Id: Ice2a9f7cad4ebe332b427bc0c7a9adccb6cf3af3

3 files changed, 33 insertions, 0 deletions

diff --git a/tools/recovery_l10n/README.md b/tools/recovery_l10n/README.md
new file mode 100644
index 00000000..bf41ff24
--- /dev/null
+++ b/tools/recovery_l10n/README.md
@@ -0,0 +1,31 @@
+# Steps to regenerate background text images under res-*dpi/images/
+
+1.  Build the recovery_l10n app:
+
+    cd bootable/recovery && mma -j32
+
+2.  Install the app on the device (or emulator) with the intended dpi.
+
+    *   For example, we can use Nexus 5 to generate the text images under
+        res-xxhdpi.
+    *   When using the emulator, make sure the NDK version matches the current
+        repository. Otherwise, the app may not work properly.
+
+    adb install $PATH_TO_APP
+
+3.  Run the app, select the string to translate and press the 'go' button.
+
+4.  After the app goes through the strings for all locales, pull the output png
+    file from the device.
+
+    adb root && adb pull /data/data/com.android.recovery_l10n/files/text-out.png
+
+5.  Compress the output file put it under the corresponding directory.
+
+    *   "pngcrush -c 0 ..." converts "text-out.png" into a 1-channel image,
+        which is accepted by Recovery. This also compresses the image file by
+        ~60%.
+    *   If you're using other png compression tools, make sure the final text
+        image works by running graphic tests under the recovery mode.
+
+    pngcrush -c 0 text-out.png $OUTPUT_PNG
diff --git a/tools/recovery_l10n/res/values/strings.xml b/tools/recovery_l10n/res/values/strings.xml
index f6193ab1..48d18dac 100644
--- a/tools/recovery_l10n/res/values/strings.xml
+++ b/tools/recovery_l10n/res/values/strings.xml
@@ -9,6 +9,7 @@
     <item>erasing</item>
     <item>no_command</item>
     <item>error</item>
+    <item>installing_security</item>
   </string-array>
 
   <!-- Displayed on the screen beneath the animated android while the
diff --git a/tools/recovery_l10n/src/com/android/recovery_l10n/Main.java b/tools/recovery_l10n/src/com/android/recovery_l10n/Main.java
index 3f2bebe6..a974fa37 100644
--- a/tools/recovery_l10n/src/com/android/recovery_l10n/Main.java
+++ b/tools/recovery_l10n/src/com/android/recovery_l10n/Main.java
@@ -139,6 +139,7 @@ public class Main extends Activity {
                     case 1: mStringId = R.string.recovery_erasing; break;
                     case 2: mStringId = R.string.recovery_no_command; break;
                     case 3: mStringId = R.string.recovery_error; break;
+                    case 4: mStringId = R.string.recovery_installing_security; break;
                 }
             }
             @Override public void onNothingSelected(AdapterView parent) { }