From cf8dcfa40cd65d1bdcb8ad3edb1c4a1eea179c3d Mon Sep 17 00:00:00 2001
From: Martin Yankov <m.i.yankov@gmail.com>
Date: Wed, 14 Mar 2018 18:15:05 +0200
Subject: [PATCH] feat(view): expose method for android back override (#5537)

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 050dbeb75..c68e4b5d8 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 646730d98..9a49221aa 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 f5af2eb0a..7e14dfb31 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 307fe8a40..1e42dfc2a 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 c4ea595e1..a07315e35 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;