Hide nav bar buttons in screen pinning dialog when appropriate.

- Also fix wrong hint text to disable screen pinning

Bug: 26314479
Change-Id: I7fc79c92511eba5e6d23dc307bb75c1710ff9e41

core/res/res/values/strings.xml

@@ -4024,7 +4024,7 @@
     <string name="date_picker_day_typeface">sans-serif-medium</string>
 
     <!-- Notify use that they are in Lock-to-app -->
-    <string name="lock_to_app_toast">To unpin this screen, touch and hold Back and Overview at the same time.</string>
+    <string name="lock_to_app_toast">To unpin this screen, touch and hold Back.</string>
     <!-- Notify use that they are in Lock-to-app in accessibility mode -->
     <string name="lock_to_app_toast_accessible">To unpin this screen, touch and hold Overview.</string>
     <!-- Notify user that they are locked in lock-to-app mode -->

packages/SystemUI/src/com/android/systemui/recents/ScreenPinningRequest.java

@@ -26,6 +26,7 @@ import android.content.Intent;
 import android.content.IntentFilter;
 import android.content.res.Configuration;
 import android.graphics.PixelFormat;
+import android.graphics.Rect;
 import android.graphics.drawable.ColorDrawable;
 import android.os.RemoteException;
 import android.util.DisplayMetrics;
@@ -204,11 +205,15 @@ public class ScreenPinningRequest implements View.OnClickListener {
             // Status bar is always on the right.
             mLayout.setLayoutDirection(View.LAYOUT_DIRECTION_LTR);
             // Buttons and text do switch sides though.
-            View buttons = mLayout.findViewById(R.id.screen_pinning_buttons);
-            buttons.setLayoutDirection(View.LAYOUT_DIRECTION_LOCALE);
             mLayout.findViewById(R.id.screen_pinning_text_area)
                     .setLayoutDirection(View.LAYOUT_DIRECTION_LOCALE);
-            swapChildrenIfRtlAndVertical(buttons);
+            View buttons = mLayout.findViewById(R.id.screen_pinning_buttons);
+            if (Recents.getSystemServices().hasSoftNavigationBar()) {
+                buttons.setLayoutDirection(View.LAYOUT_DIRECTION_LOCALE);
+                swapChildrenIfRtlAndVertical(buttons);
+            } else {
+                buttons.setVisibility(View.GONE);
+            }
 
             ((Button) mLayout.findViewById(R.id.screen_pinning_ok_button))
                     .setOnClickListener(ScreenPinningRequest.this);

packages/SystemUI/src/com/android/systemui/recents/misc/SystemServicesProxy.java

@@ -503,6 +503,18 @@ public class SystemServicesProxy {
         return false;
     }
 
+    /**
+     * Returns whether there is a soft nav bar.
+     */
+    public boolean hasSoftNavigationBar() {
+        try {
+            return WindowManagerGlobal.getWindowManagerService().hasNavigationBar();
+        } catch (RemoteException e) {
+            e.printStackTrace();
+        }
+        return false;
+    }
+
     /**
      * Cancels the current window transtion to/from Recents for the given task id.
      */