Ensure not to emit the resource ready signal during the callback

Change-Id: Icc496c34a11df14aae8b99affe846c14bca308fa

diff --git a/automated-tests/src/dali-toolkit/utc-Dali-ImageView.cpp b/automated-tests/src/dali-toolkit/utc-Dali-ImageView.cpp
index 7b0b54d..f31da7c 100644 (file)
--- a/automated-tests/src/dali-toolkit/utc-Dali-ImageView.cpp
+++ b/automated-tests/src/dali-toolkit/utc-Dali-ImageView.cpp
@@ -2749,11 +2749,20 @@ void OnResourceReadySignal( Control control )
 {
   gResourceReadySignalCounter++;
 
-  if( gResourceReadySignalCounter == 1 )
+  if(control.GetVisualResourceStatus(ImageView::Property::IMAGE) == Visual::ResourceStatus::READY)
   {
-    // Set image twice
-    ImageView::DownCast( control ).SetImage( gImage_34_RGBA );
-    ImageView::DownCast( control ).SetImage( gImage_34_RGBA );
+    if( gResourceReadySignalCounter == 1 )
+    {
+      // Set image twice
+      // It makes the first new visual be deleted immediately
+      ImageView::DownCast( control ).SetImage( gImage_34_RGBA );
+      ImageView::DownCast( control ).SetImage( gImage_34_RGBA );
+    }
+  }
+  else if(control.GetVisualResourceStatus(ImageView::Property::IMAGE) == Visual::ResourceStatus::FAILED)
+  {
+    // Make the resource ready immediately
+    control[ImageView::Property::IMAGE] = TEST_RESOURCE_DIR "/svg1.svg";
   }
 }
 
@@ -2781,5 +2790,22 @@ int UtcDaliImageViewSetImageOnResourceReadySignal(void)
 
   DALI_TEST_EQUALS( imageView.IsResourceReady(), true, TEST_LOCATION );
 
+  // Reset count
+  gResourceReadySignalCounter = 0;
+
+  imageView[ImageView::Property::IMAGE] = "invalid.jpg";
+
+  DALI_TEST_EQUALS( Test::WaitForEventThreadTrigger( 1 ), true, TEST_LOCATION );
+
+  application.SendNotification();
+  application.Render();
+
+  // Run idle callback
+  application.RunIdles();
+
+  DALI_TEST_EQUALS( gResourceReadySignalCounter, 2, TEST_LOCATION );
+
+  DALI_TEST_EQUALS( imageView.IsResourceReady(), true, TEST_LOCATION );
+
   END_TEST;
 }

diff --git a/dali-toolkit/internal/controls/control/control-data-impl.cpp b/dali-toolkit/internal/controls/control/control-data-impl.cpp
index 8a2dfd7..368ab0a 100755 (executable)
--- a/dali-toolkit/internal/controls/control/control-data-impl.cpp
+++ b/dali-toolkit/internal/controls/control/control-data-impl.cpp
@@ -26,6 +26,7 @@
 #include <dali/devel-api/scripting/scripting.h>
 #include <dali/integration-api/debug.h>
 #include <dali/public-api/object/type-registry-helper.h>
+#include <dali/integration-api/adaptor-framework/adaptor.h>
 #include <cstring>
 #include <limits>
 
@@ -322,7 +323,7 @@ Control::Impl::Impl( Control& controlImpl )
   mDownFocusableActorId( -1 ),
   mStyleName(""),
   mBackgroundColor(Color::TRANSPARENT),
-  mStartingPinchScale( NULL ),
+  mStartingPinchScale(nullptr),
   mMargin( 0, 0, 0, 0 ),
   mPadding( 0, 0, 0, 0 ),
   mKeyEventSignal(),
@@ -336,9 +337,12 @@ Control::Impl::Impl( Control& controlImpl )
   mLongPressGestureDetector(),
   mTooltip( NULL ),
   mInputMethodContext(),
+  mIdleCallback(nullptr),
   mFlags( Control::ControlBehaviour( CONTROL_BEHAVIOUR_DEFAULT ) ),
   mIsKeyboardNavigationSupported( false ),
-  mIsKeyboardFocusGroup( false )
+  mIsKeyboardFocusGroup( false ),
+  mIsEmittingResourceReadySignal(false),
+  mNeedToEmitResourceReady(false)
 {
 }
 
@@ -346,6 +350,12 @@ Control::Impl::~Impl()
 {
   // All gesture detectors will be destroyed so no need to disconnect.
   delete mStartingPinchScale;
+
+  if(mIdleCallback && Adaptor::IsAvailable())
+  {
+    // Removes the callback from the callback manager in case the control is destroyed before the callback is executed.
+    Adaptor::Get().RemoveIdle(mIdleCallback);
+  }
 }
 
 Control::Impl& Control::Impl::Get( Internal::Control& internalControl )
@@ -670,8 +680,10 @@ void Control::Impl::ResourceReady( Visual::Base& object)
   // Emit signal if all enabled visuals registered by the control are ready.
   if( IsResourceReady() )
   {
-    Dali::Toolkit::Control handle( mControlImpl.GetOwner() );
-    mResourceReadySignal.Emit( handle );
+    // Reset the flag
+    mNeedToEmitResourceReady = false;
+
+    EmitResourceReadySignal();
   }
 }
 
@@ -1448,6 +1460,58 @@ void Control::Impl::ClearShadow()
    mControlImpl.RelayoutRequest();
 }
 
+void Control::Impl::EmitResourceReadySignal()
+{
+  if(!mIsEmittingResourceReadySignal)
+  {
+    // Guard against calls to emit the signal during the callback
+    mIsEmittingResourceReadySignal = true;
+
+    // If the signal handler changes visual, it may become ready during this call & therefore this method will
+    // get called again recursively. If so, mNeedToEmitResourceReady is set below, and we act on it after that secondary
+    // invocation has completed by notifying in an Idle callback to prevent further recursion.
+    Dali::Toolkit::Control handle(mControlImpl.GetOwner());
+    mResourceReadySignal.Emit(handle);
+
+    if(mNeedToEmitResourceReady)
+    {
+      // Add idler to emit the signal again
+      if(!mIdleCallback)
+      {
+        // The callback manager takes the ownership of the callback object.
+        mIdleCallback = MakeCallback( this, &Control::Impl::OnIdleCallback);
+        Adaptor::Get().AddIdle(mIdleCallback, false);
+      }
+    }
+
+    mIsEmittingResourceReadySignal = false;
+  }
+  else
+  {
+    mNeedToEmitResourceReady = true;
+  }
+}
+
+void Control::Impl::OnIdleCallback()
+{
+  if(mNeedToEmitResourceReady)
+  {
+    // Reset the flag
+    mNeedToEmitResourceReady = false;
+
+    // A visual is ready so control may need relayouting if staged
+    if(mControlImpl.Self().GetProperty<bool>(Actor::Property::CONNECTED_TO_SCENE))
+    {
+      mControlImpl.RelayoutRequest();
+    }
+
+    EmitResourceReadySignal();
+  }
+
+  // Set the pointer to null as the callback manager deletes the callback after execute it.
+  mIdleCallback = nullptr;
+}
+
 } // namespace Internal
 
 } // namespace Toolkit

diff --git a/dali-toolkit/internal/controls/control/control-data-impl.h b/dali-toolkit/internal/controls/control/control-data-impl.h
index 43cab69..e042113 100755 (executable)
--- a/dali-toolkit/internal/controls/control/control-data-impl.h
+++ b/dali-toolkit/internal/controls/control/control-data-impl.h
@@ -386,6 +386,16 @@ private:
    */
   void RegisterVisual( Property::Index index, Toolkit::Visual::Base& visual, VisualState::Type enabled, DepthIndexValue::Type depthIndexValueSet, int depthIndex = 0 );
 
+  /**
+   * @brief Emits the resource ready signal.
+   */
+  void EmitResourceReadySignal();
+
+  /**
+   * @brief Callbacks called on idle.
+   */
+  void OnIdleCallback();
+
 public:
 
   Control& mControlImpl;
@@ -419,10 +429,13 @@ public:
   TooltipPtr mTooltip;
 
   InputMethodContext mInputMethodContext;
+  CallbackBase* mIdleCallback;             ///< The idle callback to emit the resource ready signal.
 
   ControlBehaviour mFlags : CONTROL_BEHAVIOUR_FLAG_COUNT;    ///< Flags passed in from constructor.
   bool mIsKeyboardNavigationSupported :1;  ///< Stores whether keyboard navigation is supported by the control.
   bool mIsKeyboardFocusGroup :1;           ///< Stores whether the control is a focus group.
+  bool mIsEmittingResourceReadySignal :1;  ///< True during ResourceReady().
+  bool mNeedToEmitResourceReady :1;        ///< True if need to emit the resource ready signal again.
 
   RegisteredVisualContainer mRemoveVisuals;         ///< List of visuals that are being replaced by another visual once ready