Add IGUIEnvironment::addToDeletionQueue to allow save removal of gui elements while iterating over them

Basically same as ISceneManager::addToDeletionQueue.

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@6164 dfc29bdd-3216-0410-991c-e03cc46cb475

changes.txt

@@ -1,5 +1,6 @@
 --------------------------
 Changes in 1.9 (not yet released)
+- Add IGUIEnvironment::addToDeletionQueue to allow save removal of gui elements while iterating over them (like the same named function in ISceneManager).
 - IGUIEnvironment::drawAll has now a parameter to allow disabling automatic resize to screensize. Makes it easier to use partial screens with full alignment support.
 - No longer try to set WM_QUIT when using an external Window on Win32. 
   Thx @Marko Mahnic for the patch (https://sourceforge.net/p/irrlicht/bugs/449)

include/IGUIEnvironment.h

@@ -623,10 +623,10 @@ public:
 	virtual void deserializeAttributes(io::IAttributes* in, io::SAttributeReadWriteOptions* options=0)=0;
 
 	//! writes an element
-	virtual void writeGUIElement(io::IXMLWriter* writer, IGUIElement* node) =0;
+	virtual void writeGUIElement(io::IXMLWriter* writer, IGUIElement* element) =0;
 
 	//! reads an element
-	virtual void readGUIElement(io::IXMLReader* reader, IGUIElement* node) =0;
+	virtual void readGUIElement(io::IXMLReader* reader, IGUIElement* element) =0;
 
 	//! Find the next element which would be selected when pressing the tab-key
 	/** If you set the focus for the result you can manually force focus-changes like they
@@ -646,6 +646,17 @@ public:
 	//! Get the way the gui does handle focus changes
 	/** \returns A bitmask which is a combination of ::EFOCUS_FLAG flags.*/
 	virtual u32 getFocusBehavior() const = 0;
+
+	//! Adds a IGUIElement to deletion queue.
+	/** Queued elements will be removed at the end of each drawAll call.
+	Or latest in the destructor of the GUIEnvironment.
+	This can be used to allow an element removing itself safely in a function 
+	iterating over gui elements, like an overloaded	IGUIElement::draw or 
+	IGUIElement::OnPostRender function.
+	Note that in general just calling IGUIElement::remove() is enough. 
+	Unless you create your own GUI elements removing themselves you won't need it.
+	\param element: Element to remove */
+	virtual void addToDeletionQueue(IGUIElement* element) = 0;
 };
 
 

source/Irrlicht/CGUIEnvironment.cpp

@@ -101,6 +101,8 @@ CGUIEnvironment::CGUIEnvironment(io::IFileSystem* fs, video::IVideoDriver* drive
 //! destructor
 CGUIEnvironment::~CGUIEnvironment()
 {
+	clearDeletionQueue();
+
 	if ( HoveredNoSubelement && HoveredNoSubelement != this )
 	{
 		HoveredNoSubelement->drop();
@@ -212,6 +214,8 @@ void CGUIEnvironment::drawAll(bool useScreenSize)
 
 	draw();
 	OnPostRender ( os::Timer::getTime () );
+
+	clearDeletionQueue();
 }
 
 
@@ -470,6 +474,28 @@ void CGUIEnvironment::OnPostRender( u32 time )
 	IGUIElement::OnPostRender ( time );
 }
 
+void CGUIEnvironment::addToDeletionQueue(IGUIElement* element)
+{
+	if (!element)
+		return;
+
+	element->grab();
+	DeletionQueue.push_back(element);
+}
+
+void CGUIEnvironment::clearDeletionQueue()
+{
+	if (DeletionQueue.empty())
+		return;
+
+	for (u32 i=0; i<DeletionQueue.size(); ++i)
+	{
+		DeletionQueue[i]->remove();
+		DeletionQueue[i]->drop();
+	}
+
+	DeletionQueue.clear();
+}
 
 //
 void CGUIEnvironment::updateHoveredElement(core::position2d<s32> mousePos)

source/Irrlicht/CGUIEnvironment.h

@@ -269,8 +269,14 @@ public:
 	//! Get the way the gui does handle focus changes
 	virtual u32 getFocusBehavior() const _IRR_OVERRIDE_;
 
+	//! Adds a IGUIElement to deletion queue.
+	virtual void addToDeletionQueue(IGUIElement* element) _IRR_OVERRIDE_;
+
 private:
 
+	//! clears the deletion queue
+	void clearDeletionQueue();
+
 	void updateHoveredElement(core::position2d<s32> mousePos);
 
 	void loadBuiltInFont();
@@ -322,6 +328,8 @@ private:
 	IEventReceiver* UserReceiver;
 	IOSOperator* Operator;
 	u32 FocusFlags;
+	core::array<IGUIElement*> DeletionQueue;
+
 	static const io::path DefaultFontName;
 };