Keep controllers attached but hide them, instead of removing the view

Previously when a controller because hidden, it was removed from the view hierachy, and reattached when shown again.
Now the views are only detached from the view hierachy when the whole controller gets destroyed, and the view visibility is changed on onHide and onShow.
This was done for performance reasons. Reattaching a controller takes too much time and is noticable when trying to swipe a controller away.

Clover/app/src/main/java/org/floens/chan/controller/Controller.java

@@ -21,6 +21,7 @@ import android.content.Context;
 import android.content.res.Configuration;
 import android.view.KeyEvent;
 import android.view.LayoutInflater;
+import android.view.View;
 import android.view.ViewGroup;
 
 import org.floens.chan.controller.transition.FadeInTransition;
@@ -82,6 +83,8 @@ public abstract class Controller {
             Logger.test(getClass().getSimpleName() + " onShow");
         }
 
+        view.setVisibility(View.VISIBLE);
+
         for (Controller controller : childControllers) {
             if (!controller.shown) {
                 controller.onShow();
@@ -95,6 +98,8 @@ public abstract class Controller {
             Logger.test(getClass().getSimpleName() + " onHide");
         }
 
+        view.setVisibility(View.GONE);
+
         for (Controller controller : childControllers) {
             if (controller.shown) {
                 controller.onHide();
@@ -111,6 +116,10 @@ public abstract class Controller {
         while (childControllers.size() > 0) {
             removeChildController(childControllers.get(0));
         }
+
+        if (AndroidUtils.removeFromParentView(view)) {
+            Logger.test(getClass().getSimpleName() + " view removed onDestroy");
+        }
     }
 
     public void addChildController(Controller controller) {
@@ -125,29 +134,22 @@ public abstract class Controller {
         return childControllers.remove(controller);
     }
 
-    public void attach(ViewGroup parentView, boolean over) {
+    public void attachToParentView(ViewGroup parentView, boolean over) {
-        ViewGroup.LayoutParams params = view.getLayoutParams();
+        if (view.getParent() != null) {
-
+            if (LOG_STATES) {
-        if (params == null) {
+                Logger.test(getClass().getSimpleName() + " view removed");
-            params = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
+            }
-        } else {
+            AndroidUtils.removeFromParentView(view);
-            params.width = ViewGroup.LayoutParams.MATCH_PARENT;
-            params.height = ViewGroup.LayoutParams.MATCH_PARENT;
         }
 
-        view.setLayoutParams(params);
+        if (parentView != null) {
-
+            if (LOG_STATES) {
-        if (over) {
+                Logger.test(getClass().getSimpleName() + " view attached");
-            parentView.addView(view, view.getLayoutParams());
+            }
-        } else {
+            attachToView(parentView, over);
-            parentView.addView(view, 0, view.getLayoutParams());
         }
     }
 
-    public void detach() {
-        AndroidUtils.removeFromParentView(view);
-    }
-
     public void onConfigurationChanged(Configuration newConfig) {
         for (Controller controller : childControllers) {
             controller.onConfigurationChanged(newConfig);
@@ -186,7 +188,7 @@ public abstract class Controller {
         controller.presentingByController = this;
 
         controller.onCreate();
-        controller.attach(contentView, true);
+        controller.attachToView(contentView, true);
         controller.onShow();
 
         if (animated) {
@@ -223,7 +225,6 @@ public abstract class Controller {
 
     private void finishPresenting() {
         onHide();
-        detach();
         onDestroy();
     }
 
@@ -238,4 +239,23 @@ public abstract class Controller {
     public ViewGroup inflateRes(int resId) {
         return (ViewGroup) LayoutInflater.from(context).inflate(resId, null);
     }
+
+    private void attachToView(ViewGroup parentView, boolean over) {
+        ViewGroup.LayoutParams params = view.getLayoutParams();
+
+        if (params == null) {
+            params = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
+        } else {
+            params.width = ViewGroup.LayoutParams.MATCH_PARENT;
+            params.height = ViewGroup.LayoutParams.MATCH_PARENT;
+        }
+
+        view.setLayoutParams(params);
+
+        if (over) {
+            parentView.addView(view, view.getLayoutParams());
+        } else {
+            parentView.addView(view, 0, view.getLayoutParams());
+        }
+    }
 }

Clover/app/src/main/java/org/floens/chan/controller/NavigationController.java

@@ -89,7 +89,6 @@ public abstract class NavigationController extends Controller {
             throw new IllegalArgumentException("Cannot transition while another transition is in progress.");
         }
 
-        to.attach(container, false);
         to.onShow();
 
         return true;
@@ -101,11 +100,9 @@ public abstract class NavigationController extends Controller {
     public void endSwipeTransition(final Controller from, final Controller to, boolean finish) {
         if (finish) {
             from.onHide();
-            from.detach();
             removeChildController(from);
         } else {
             to.onHide();
-            to.detach();
         }
 
         controllerTransition = null;
@@ -126,7 +123,7 @@ public abstract class NavigationController extends Controller {
         }
 
         if (to != null) {
-            to.attach(container, pushing);
+            to.attachToParentView(container, pushing);
             to.onShow();
         }
 
@@ -158,7 +155,6 @@ public abstract class NavigationController extends Controller {
     private void finishTransition(Controller from, boolean pushing) {
         if (from != null) {
             from.onHide();
-            from.detach();
         }
 
         if (!pushing && from != null) {

Clover/app/src/main/java/org/floens/chan/ui/controller/DrawerController.java

@@ -115,7 +115,7 @@ public class DrawerController extends Controller implements PinAdapter.Callback,
 
     public void setChildController(Controller childController) {
         addChildController(childController);
-        childController.attach(container, true);
+        childController.attachToParentView(container, true);
         childController.onShow();
     }
 

Clover/app/src/main/java/org/floens/chan/ui/controller/PopupController.java

@@ -45,7 +45,7 @@ public class PopupController extends Controller implements View.OnClickListener
 
     public void setChildController(NavigationController childController) {
         addChildController(childController);
-        childController.attach(container, true);
+        childController.attachToParentView(container, true);
         childController.onShow();
     }
 

Clover/app/src/main/java/org/floens/chan/ui/controller/SplitNavigationController.java

@@ -82,7 +82,6 @@ public class SplitNavigationController extends Controller implements AndroidUtil
     public void setLeftController(Controller leftController) {
         if (this.leftController != null) {
             this.leftController.onHide();
-            this.leftController.detach();
             removeChildController(this.leftController);
         }
 
@@ -90,17 +89,14 @@ public class SplitNavigationController extends Controller implements AndroidUtil
 
         if (leftController != null) {
             addChildController(leftController);
-            leftController.attach(leftControllerView, true);
+            leftController.attachToParentView(leftControllerView, true);
             leftController.onShow();
-        } else {
-
         }
     }
 
     public void setRightController(Controller rightController) {
         if (this.rightController != null) {
             this.rightController.onHide();
-            this.rightController.detach();
             removeChildController(this.rightController);
         } else {
             rightControllerView.removeAllViews();
@@ -110,7 +106,7 @@ public class SplitNavigationController extends Controller implements AndroidUtil
 
         if (rightController != null) {
             addChildController(rightController);
-            rightController.attach(rightControllerView, true);
+            rightController.attachToParentView(rightControllerView, true);
             rightController.onShow();
         } else {
             rightControllerView.addView(emptyView);