handle back pressed event

Author: codeanticode

core/src/processing/android/ActivityAPI.java

@@ -52,4 +52,7 @@ public interface ActivityAPI {
   public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo);
   public boolean onContextItemSelected(MenuItem item);
   public void setHasOptionsMenu(boolean hasMenu);
+
+  // IO events
+  public void onBackPressed();
 }

core/src/processing/core/PApplet.java

@@ -260,6 +260,11 @@ public class PApplet extends Object implements ActivityAPI, PConstants {
    */
   boolean keyboardIsOpen = false;
 
+  /**
+   * Flag to determine if the user handled the back press.
+   */
+  public boolean handledBackPressed = true;
+
   ///////////////////////////////////////////////////////////////
   // Permission handling
 
@@ -555,6 +560,10 @@ public void onResume() {
       resume();
     }
 
+    // Set the default to true to handle the situation where a fragment is popping back
+    // after pressing back (app does not exit)
+    handledBackPressed = true;
+
     surface.resumeThread();
   }
 
@@ -631,6 +640,10 @@ public void setHasOptionsMenu(boolean hasMenu) {
   }
 
 
+  public void onBackPressed() {
+    handledBackPressed = false;
+  }
+
   public void startActivity(Intent intent) {
     surface.startActivity(intent);
   }

mode/templates/AppActivity.java.tmpl

@@ -42,4 +42,13 @@ public class MainActivity extends AppCompatActivity {
       sketch.onNewIntent(intent);
     }  
   }
+  
+  @Override
+  public void onBackPressed() {
+    if (sketch != null) {
+      sketch.onBackPressed();
+      if (sketch.handledBackPressed) return;
+    }
+    super.onBackPressed();
+  }  
 }

mode/templates/VRActivity.java.tmpl

@@ -6,11 +6,22 @@ import processing.vr.PVR;
 import processing.core.PApplet;
 
 public class MainActivity extends PVR {
+  private PApplet sketch;
+  
   @Override
   public void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
-    PApplet sketch = new @@sketch_class_name@@();
+    sketch = new @@sketch_class_name@@();
     @@external@@
     setSketch(sketch);
   }
+  
+  @Override
+  public void onBackPressed() {
+    if (sketch != null) {
+      sketch.onBackPressed();
+      if (sketch.handledBackPressed) return;
+    }
+    super.onBackPressed();
+  }  
 }

studio/apps/simple/src/main/java/simple/MainActivity.java

@@ -40,4 +40,13 @@ public void onNewIntent(Intent intent) {
       sketch.onNewIntent(intent);
     }
   }
+
+  @Override
+  public void onBackPressed() {
+    if (sketch != null) {
+      sketch.onBackPressed();
+      if (sketch.handledBackPressed) return;
+    }
+    super.onBackPressed();
+  }
 }

studio/apps/vrcube/src/main/java/vrcube/MainActivity.java

@@ -6,11 +6,22 @@
 import processing.core.PApplet;
 
 public class MainActivity extends PVR {
+  private PApplet sketch;
+
   @Override
   public void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
-    PApplet sketch = new Sketch();
+    sketch = new Sketch();
     sketch.setExternal(true);
     setSketch(sketch);
   }
+
+  @Override
+  public void onBackPressed() {
+    if (sketch != null) {
+      sketch.onBackPressed();
+      if (sketch.handledBackPressed) return;
+    }
+    super.onBackPressed();
+  }
 }