From: Alexis Laferrière <alexis.laf@xymus.net>
Date: Fri, 18 Mar 2016 20:17:59 +0000 (-0400)
Subject: lib/android: implement back_button support using the "hardware" back key
X-Git-Url: http://nitlanguage.org

lib/android: implement back_button support using the "hardware" back key

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
---

diff --git a/lib/android/NitActivity.java b/lib/android/NitActivity.java
index 8837617..cbe6ad4 100644
--- a/lib/android/NitActivity.java
+++ b/lib/android/NitActivity.java
@@ -48,6 +48,7 @@ public class NitActivity extends Activity {
 	protected native void nitOnDestroy(int activity);
 	protected native void nitOnSaveInstanceState(int activity, Bundle savedInstanceState);
 	protected native void nitOnRestoreInstanceState(int activity, Bundle savedInstanceState);
+	protected native boolean nitOnBackPressed(int activity);
 	protected native boolean nitOnKeyDown(int activity, int keyCode, KeyEvent event);
 	protected native boolean nitOnKeyLongPress(int activity, int keyCode, KeyEvent event);
 	protected native boolean nitOnKeyMultiple(int activity, int keyCode, int count, KeyEvent event);
@@ -115,6 +116,12 @@ public class NitActivity extends Activity {
 	}
 
 	@Override
+	public void onBackPressed() {
+		if (!nitOnBackPressed(nitActivity))
+			super.onBackPressed();
+	}
+
+	@Override
 	public boolean onKeyDown(int keyCode, KeyEvent event) {
 		return nitOnKeyDown(nitActivity, keyCode, event)
 			|| super.onKeyDown(keyCode, event);
diff --git a/lib/android/nit_activity.nit b/lib/android/nit_activity.nit
index de849ea..1668147 100644
--- a/lib/android/nit_activity.nit
+++ b/lib/android/nit_activity.nit
@@ -135,6 +135,12 @@ in "C body" `{
 		Activity_on_restore_instance_state((Activity)nit_activity, saved_state);
 	}
 
+	JNIEXPORT jboolean JNICALL Java_nit_app_NitActivity_nitOnBackPressed
+	  (JNIEnv *env, jobject java_activity, jint nit_activity)
+	{
+		return (jboolean)Activity_on_back_pressed((Activity)nit_activity);
+	}
+
 	JNIEXPORT jboolean JNICALL Java_nit_app_NitActivity_nitOnKeyDown
 	  (JNIEnv *env, jobject java_activity, jint nit_activity, jint keyCode, jobject event)
 	{
@@ -184,6 +190,7 @@ redef class App
 	Activity.on_start, Activity.on_restart, Activity.on_stop,
 	Activity.on_pause, Activity.on_resume,
 	Activity.on_save_instance_state, Activity.on_restore_instance_state,
+	Activity.on_back_pressed,
 	Activity.on_key_down, Activity.on_key_long_press,
 	Activity.on_key_multiple, Activity.on_key_up `{
 		App_incr_ref(self);
@@ -279,6 +286,11 @@ class Activity
 	# Notification from Android, the current device configuration has changed
 	fun on_configuration_changed do end
 
+	# The back key has been pressed
+	#
+	# Return `true` if the event has been handled.
+	fun on_back_pressed: Bool do return false
+
 	# A key has been pressed
 	#
 	# Return `true` if the event has been handled.
diff --git a/lib/android/ui/ui.nit b/lib/android/ui/ui.nit
index 65535e8..dedad21 100644
--- a/lib/android/ui/ui.nit
+++ b/lib/android/ui/ui.nit
@@ -78,6 +78,19 @@ redef class App
 	end
 end
 
+redef class Activity
+	redef fun on_back_pressed
+	do
+		var window = app.window
+		if window.enable_back_button then
+			window.on_back_button
+			return true
+		end
+
+		return false
+	end
+end
+
 # On Android, a window is implemented with the fragment `native`
 redef class Window
 	redef var native = (new Android_app_Fragment(self)).new_global_ref