Fix Bug 677: NEWT/Android: Add support for Android's KeyEvent.KEYCODE_BACK

Original author: Eric Brayet <[email protected]>
Revised by: Sven Gothel <[email protected]>

I took the freedom to cleanup the three original patches
from https://github.com/Pooouf/jogl.git branch 'bug_677':
  - 7449d4726633d524a3bb79efffd04cfd0ca25e58 (removed by followup patch!)
  - 68c739a4f03e46deecdbb71c125b4586aec08d63 (removes previous patch!)
  - c2813dfc325a1482d18b6fc304e4e483f5633964

Further more I was able to reduce the 'extra' code while utilizing
  - Window's isKeyboardVisible() and using keyboardVisibilityChanged(false)
    to update the hidden keyboard state.
  - Moving the key-handling code to the containing WindowDriver class
    avoiding passing a reference to the inner view.
  - Using AndroidNewtEventFactory for NEWT KeyEvent creation

+++

- Handle KeyEvent.KEYCODE_BACK w/ jogamp.newt.driver.android.WindowDriver.MSurfaceView.onKeyPreIme(..):
    if( soft keyboard is up )
      [1] Update keyboard visibility state and return NEWT KeyEvent.VK_KEYBOARD_INVISIBLE;
    else
      [2] call WindowImpl.windowDestroyNotify(true)

    [3] then cont. processing, i.e. return false;

- Turns out respecting WindowClosingMode might be
  - too complicated
  - interfere w/ Android UI behavior

- AndroidNewtEventFactory
  - createKeyEvent
    - static
    - adding boolean param 'inclSysKeys', if true, KEYCODE_BACK and KEYCODE_HOME are mapped

- Unit tests: GearsES2 + MovieCubeActivity0 shows keyboard if pressure > 0.6f
    - pressure on Android shall be between [0..1], however we have to figure out
      badly calibrated touchpads/Android device where we could experience
      pressure > 2.0f !

    - TODO: API documentation of pressure [0..1]

2 files changed, 6 insertions, 1 deletions

diff --git a/src/newt/classes/com/jogamp/newt/event/KeyEvent.java b/src/newt/classes/com/jogamp/newt/event/KeyEvent.java
index f626fec38..5117ffe29 100644
--- a/src/newt/classes/com/jogamp/newt/event/KeyEvent.java
+++ b/src/newt/classes/com/jogamp/newt/event/KeyEvent.java
@@ -872,6 +872,11 @@ public class KeyEvent extends InputEvent
     public static final short VK_BEGIN                    = (short) 0xFF58;
 
     /**
+     * Constant for Keyboard became invisible, e.g. Android's soft keyboard Back button hit while keyboard is visible.
+     */
+    public static final short VK_KEYBOARD_INVISIBLE       = (short) 0xDEAD;
+
+    /**
      * This value is used to indicate that the keyCode is unknown.
      * KEY_TYPED events do not have a keyCode value; this value 
      * is used instead.  
diff --git a/src/newt/classes/com/jogamp/newt/event/NEWTEvent.java b/src/newt/classes/com/jogamp/newt/event/NEWTEvent.java
index 6f4561ce6..17210cef8 100644
--- a/src/newt/classes/com/jogamp/newt/event/NEWTEvent.java
+++ b/src/newt/classes/com/jogamp/newt/event/NEWTEvent.java
@@ -107,7 +107,7 @@ public class NEWTEvent extends java.util.EventObject {
         return sb.append("NEWTEvent[source:").append(getSource().getClass().getName()).append(", when:").append(getWhen()).append(" d ").append((System.currentTimeMillis()-getWhen())).append("ms]");
     }
 
-    static String toHexString(short hex) {
+    public static String toHexString(short hex) {
         return "0x" + Integer.toHexString( (int)hex & 0x0000FFFF );
     }
 }