From 80178e43773f4ddf56255fc7e0a89627190d5901 Mon Sep 17 00:00:00 2001
From: Martin Yankov <m.i.yankov@gmail.com>
Date: Wed, 14 Mar 2018 13:22:42 +0200
Subject: [PATCH] feat(view): expose method for android back override

Expose method on View class onBackPressed(). Third party controls
like RadSideDrawer can use this method to override the default Android
back button handling. By default the app closes.
---
 tns-core-modules/ui/core/view/view-common.ts     | 2 +-
 tns-core-modules/ui/core/view/view.android.ts    | 2 +-
 tns-core-modules/ui/core/view/view.d.ts          | 5 +++--
 tns-core-modules/ui/frame/frame.android.ts       | 4 ++--
 tns-core-modules/ui/tab-view/tab-view.android.ts | 4 ++--
 5 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/tns-core-modules/ui/core/view/view-common.ts b/tns-core-modules/ui/core/view/view-common.ts
index 050dbeb75a..c68e4b5d81 100644
--- a/tns-core-modules/ui/core/view/view-common.ts
+++ b/tns-core-modules/ui/core/view/view-common.ts
@@ -203,7 +203,7 @@ export abstract class ViewCommon extends ViewBase implements ViewDefinition {
         return false;
     }
 
-    public _onBackPressed(): boolean {
+    public onBackPressed(): boolean {
         return false;
     }
 
diff --git a/tns-core-modules/ui/core/view/view.android.ts b/tns-core-modules/ui/core/view/view.android.ts
index 646730d980..9a49221aae 100644
--- a/tns-core-modules/ui/core/view/view.android.ts
+++ b/tns-core-modules/ui/core/view/view.android.ts
@@ -115,7 +115,7 @@ function initializeDialogFragment() {
             };
             view.notify(args);
 
-            if (!args.cancel && !view._onBackPressed()) {
+            if (!args.cancel && !view.onBackPressed()) {
                 super.onBackPressed();
             }
         }
diff --git a/tns-core-modules/ui/core/view/view.d.ts b/tns-core-modules/ui/core/view/view.d.ts
index f5af2eb0a4..7e14dfb317 100644
--- a/tns-core-modules/ui/core/view/view.d.ts
+++ b/tns-core-modules/ui/core/view/view.d.ts
@@ -678,10 +678,11 @@ export abstract class View extends ViewBase {
      * @private
      */
     _onLivesync(): boolean;
+
     /**
-     * @private
+     * Derived classes can override this method to handle Android back button press. 
      */
-    _onBackPressed(): boolean;
+    onBackPressed(): boolean;
     /**
      * @private
      */
diff --git a/tns-core-modules/ui/frame/frame.android.ts b/tns-core-modules/ui/frame/frame.android.ts
index 307fe8a408..1e42dfc2a8 100644
--- a/tns-core-modules/ui/frame/frame.android.ts
+++ b/tns-core-modules/ui/frame/frame.android.ts
@@ -249,7 +249,7 @@ export class Frame extends FrameBase {
         }
     }
 
-    public _onBackPressed(): boolean {
+    public onBackPressed(): boolean {
         if (this.canGoBack()) {
             this.goBack();
             return true;
@@ -884,7 +884,7 @@ class ActivityCallbacksImplementation implements AndroidActivityCallbacks {
             };
             view.notify(viewArgs);
 
-            if (!viewArgs.cancel && !view._onBackPressed()) {
+            if (!viewArgs.cancel && !view.onBackPressed()) {
                 callSuper = true;
             }
         }
diff --git a/tns-core-modules/ui/tab-view/tab-view.android.ts b/tns-core-modules/ui/tab-view/tab-view.android.ts
index c4ea595e1d..a07315e353 100644
--- a/tns-core-modules/ui/tab-view/tab-view.android.ts
+++ b/tns-core-modules/ui/tab-view/tab-view.android.ts
@@ -510,10 +510,10 @@ export class TabView extends TabViewBase {
         super.disposeNativeView();
     }
 
-    public _onBackPressed(): boolean {
+    public onBackPressed(): boolean {
         const currentView = this._selectedView;
         if (currentView) {
-            return currentView._onBackPressed();
+            return currentView.onBackPressed();
         }
 
         return false;