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This article has been re-structured and can be found in its new format here: User Interface

Overview

The UI Action system allows to setup and control any Flash UI element using flowgraph.

For this purpose every Flash asset can be defined in an XML file with all events, functions, and variables that need to be available in the flowgraphs.

How to setup materials for flash use can be found here: UI Elements as Dynamic Textures.

Setup XML files for Flash assets

The Flash UI system reads all XML files located in Game/Libs/UI/UIElements and creates flownodes to control the Flash assets.

Open an existing XML file or create a new one to define a new UI element.

Basic definition of a Flash asset:

hud.xml
<UIElements name="HudElements"> <!-- Group name for this elements -->

  <!-- definition of an UI element named "HUD" -->
  <UIElement name="HUD">

    <!-- gfx/swf file for this UI element -->
    <GFx file="HUD.gfx" layer="1">
      <!-- the align mode of this element -->
      <Constraints>
        <Align mode="dynamic" halign="center" valign="center" scale="1" max="1" />
      </Constraints>
    </GFx>

    <!-- available functions -->
    <functions>
    </functions>

    <!-- available events that are raised by the Flash asset -->
    <events>
    </events>

    <!-- available variables -->
    <variables>
    </variables>

    <!-- available arrays -->
    <arrays>
    </arrays>

    <!-- available movieclips -->
    <movieclips>
    </movieclips>

  </UIElement>

  <!-- definition of another UI element named "LoadingScreen" -->
  <UIElement name="LoadingScreen">
      ...
  </UIElement>

</UIElements>

Functions

Functions that should be callable from outside need to be defined in the <functions> list of the element.

e.g. an actionscript function to set a health bar:

actionscrpit
function setHealth(iHealth:Number):void
{
  // set a health bar
}

can be defined in the xml as:

hud.xml
<function name="SetHealth" funcname="setHealth">
  <param name="Health" desc="Players current health"/>
</function>

where name="..." is the name of the function that is visible in the flowgraph and funcname="..." is the real name of the function in the actionscript.

The system will automatically create a node for the flowgraph to call this function.

Note: It is also possible to define functions that are not in the rootspace of the Flash file, e.g.

hud.xml
<function name="SetHealth" funcname="myHealthMc.mysubmc.setHealth">
  <param name="Health" desc="Players current health"/>
</function>

Events

To get notification about some user interaction, e.g. if a button was pressed, events can be defined in the <events> list. To trigger an event in your actionscript code you have to call fscommand("commandString"). These fscommands are handled by the engine.

e.g. in the onPress function of a button you can call fscommand with the string "onMyButtonPressed" and some arguments.

actionscrpit
myButton.onPress = function()
{
  var args:Array = new Array();
  args.push(argument1);
  args.push(argument2);
  fscommand("onMyButtonPressed", args);
}

To handle this event add a <event> tag into the <events> list

hud.xml
<event name="OnButton1" fscommand="onMyButtonPressed">
  <param name="Arg1" desc="Some argument"/>
  <param name="Arg2" desc="Another argument"/>
</event>

The system creates a node to handle this event.

Variables, Arrays and MovieClips

Access to an array or a variable can also be defined in the xml file.

Just add a <variable> tag into the <variables> list, an <array> tag to the <arrays> list or a <movieclip> tag into the <movieclips> list.

hud.xml
<variables>
  <variable name="SomeVariable" varname="someVariable"/>
  <variable name="TextField" varname="_root.myTextfield.text"/>
</variables>

<arrays>
  <array name="SomeArray" varname="_root.mc2.someArray"/>
</arrays>

<movieclips>
  <movieclip name="MovieClip1" instancename="_root.Mc1"/>
  <movieclip name="MovieClip2" instancename="_root.Mc1.subMc"/>
</movieclips>

To get or set a variable select the variable in the dropdown list of the UI:Variable:Var or UI:Variable:Array flownode.


Note: Arrays are comma separated strings.

You can also access your defined MovieClips via FlowNodes.

Display / hide and setup gfx files

To show or hide a Flash asset use the UI:Display:Display node. You can select the element in the dropdown list.

To setup the behavior and the constraints use the UI:Display:Constraints and UI:Display:Config nodes.

It is also possible to initialize all of those settings in the xml file.

hud.xml
<UIElement name="HUD" mouseevents="1" keyevents="1" cursor="1" console_mouse="1" console_cursor="1">
  <GFx file="HUD.gfx" layer="1" alpha="0.5">
    <!-- the align mode of this element -->
    <Constraints>
      <Align mode="fullscreen" />

      <!-- <Align mode="dynamic" halign="center" valign="center" scale="1" max="1" /> -->

      <!-- <Align mode="fixed" /> -->
      <!-- <Position top="20" left="20" width="200" height="200" /> -->

    </Constraints>
  </GFx>
  ...
</UIElement>

Configuration

  • mouseevents
    0=disable, 1=enabled, if enabled mouse events are send to the Flash file (mouse-clicks and movement)
  • cursor
    0=disabled, 1=enabled, if enabled a hardware mouse cursor is visible while the Flash element is displayed.
  • keyevents
    0=disabled, 1=enabled, if enabled keyevents are send to the Flash element.
  • console_mouse
    0=disabled, 1=enabled, if enabled the controller works as a mouse on console (thumb-stick). Only if mouseevents are enabled.
  • console_cursor
    0=diabled, 1=enabled, if enabled a hardware cursor is displayed on console as well. Only if cursor is enabled.
  • layer
    0 to n, defines in which order the elements are displayed (if more than one Flash element is visible).
  • alpha
    0 to 1, the background alpha of the Flash element.

Constraints

There are three modes to place the asset on the screen:

  • "fixed"
    in this mode the Flash asset is displayed on a fixed position, defined by a top, left, width and height value.
  • "dynamic"
    this mode aligns the asset on anchors. For vertical alignment it is possible to align the Flash element at the "top", "center" or "bottom", for horizontal alignment to the "left", "center" or "right" of the screen.

If scale is "1" it tries to scale the element to the maximum without deforming the aspect ratio. If scale is set to "0", it will not scale the Flash asset.
If max is set to "1" it will maximize the element so that 100% of the screen is covered (this might cause that some parts of the element are cut-off) otherwise the asset will fit to the screen with maybe some uncovered space on the left/right or top/bottom side.

  • "fullscreen"
    In this mode the viewport of the asset is same as the render viewport. If scale is set to "1" the asset is stretched to fit the complete screen, otherwise not.

Instantiation of Elements

Each node has the "InstanceID" port. With this instance ID you can have more than one instance of any Flash asset. The "InstanceID" port of any UI node defines which instance should be affected by this node. If you use a node with a new instance ID it will automaticly create the new instance of this Flash asset. If you use "-1" as the instance ID, the node will affect all instances of this Flash element.

Helpful functions

There are some special actionscript functions that are automatically called by the UI system.

These functions can be defined in the rootspace of your actionscript and don't need to be defined in the xml file.

Actionscript functions

cry_onSetup
If this function exists, it is called once the gfx/swf file is loaded by the engine.

function cry_onSetup(_bIsConsole) // true if running on console, false for pc


cry_onShow
If this function exists, it is called once the gfx/swf file is shown up.

function cry_onShow()


cry_onHide
If this function exists, it is called once the gfx/swf file is hided.

function cry_onHide()


cry_onResize
If this function exists, it is called once the resolution of the engine has changed.

function cry_onResize(_intWidth, _intHeight)


cry_onBack
If this function exists, it is called once if the player pressed the back button on the controller.

function cry_onBack()


cry_requestHide
This function is called if the "RequestHide" port was triggered on the UI:Display:Display Node (or via code / Lua). Can be used to fade out elements.

function cry_requestHide()

fscommands

There are some fscommand strings that can be called within your actionscript.

cry_hideElement
If a fscommand is executed with this string, it tells the UI System to hide the element.

fscommand("cry_hideElement");

Example

Fade UI Element in / out.

// create onEnterFrame function to fade-in the root element (if UI Element is shown up)
function cry_onShow()
{
   _root._alpha = 0;
   onEnterFrame = function()
   {
      if (_root._alpha < 100)
      {
         _root._alpha++;
      }
      else
      {
         // clear onEnterFrame function
         onEnterFrame = function() {};
      }
   }
}

// create onEnterFrame function to fade-out the root element (if requested by UI System)
function cry_requestHide()
{
   onEnterFrame = function()
   {
      if (_root._alpha > 0)
      {
         _root._alpha--;
      }
      else
      {
         // clear onEnterFrame function and notify UI-System that this element does not need to be drawn anymore.
         onEnterFrame = function() {};
         fscommand("cry_hideElement");
      }
   }
}

You can now fade in/out the element by triggering the port show / requestHide if the UI:Display:Display Node.

UI Flowgraphs

To create a new flowgraph for the UI just open the Flowgraph and choose "File->New UI Action...".

All UI Actions are located in the Flow Graphs list and the xml files needs to be saved in Game/Libs/UI/UIActions.

Note: All UI actions are saved separate from the level. They need to be saved via File->Save in the flowgraph menu. Make sure to save every time you did some changes!

You find all flownodes for the UI in the component list unter UI.

Example

This example shows a simple flowgraph to show/hide a loading screen and setup the level name and a progress value.

The associated element is defined in Game/Libs/UI/UIElements/Menus.xml

Menus.xml
<UIElement name="LoadingScreen">

  <GFx file="LoadingScreen.gfx" layer="2" alpha="1" >
    <Constraints>
      <Align mode="fullscreen" />
    </Constraints>
  </GFx>

  <variables>
    <variable name="Percent" varname="LoadingPanel.Percent.text"/>
    <variable name="LevelName" varname="LoadingPanel.Level.text"/>
  </variables>

</UIElement>

UI Actions

Sometimes it is helpful to trigger a complex UI Action several times without rebuilding the whole graph every time.

For this purpose it is possible to create UI Actions with a "UI:Action:Start" and "UI:Action:End" node. You will find this nodes under UI:Action.

The Name of the Flowgraph defines the Name of the Action.

The "UI:Action:Control" node allows to start an UI Action and receive notifications if an action was started or stopped.

It is also possible to pass several arguments to an UIAction via the "UI:Action:Control" node.

As an example the UIAction to display a USM Video file:

This action can be used e.g. to play a movie on enter a proximity trigger:

Note: You can control any UI action from any flowgraph. If you disable an UI Action, the complete flowgraph will be disabled (not only the Nodes between the start and end node). It is also possible to use the StartAction and EndAction notes more than once per flowgraph. Every StartAction node will be triggered if the action is started and the first reached EndAction node will trigger the OnEnd port of any UI:Action:Control node which is listening to the flowgraph.

Lua and Flash UI System

It is also possible to control the UI System via Lua. See also: List of Lua functions.

Example

  	// Display UI Element
  	UIAction.ShowElement("MyUIElement", 0);

  	// Call actionscript
  	UIAction.CallFunction("MyUIElement", 0, "Foo", "paramStr1", "paramStr2", 123, 12.3, false);

  	// set variable
  	UIAction.SetVariable("MyUIElement", 0, "MyVariable", 23);

   	// get variable
 	local var1 = UIAction.GetVariable("MyUIElement", 0, "MyVariable");
  	if (var1) then
  	   Log("Var1: %d", var1);
  	end

	// set array
  	local newValues = {
		"val1",
		"val2",
		"val3",
	};
  	UIAction.SetArray("MyUIElement", 0, "MyArray", newValues);

	// get array
	local values = UIAction.GetArray("MyUIElement", 0, "MyArray");
	local value;
	if (values) then
   	   for i,value in ipairs(values) do
   	     Log("Value: %s", value);
	   end
	end

Communication between C++ and UI flowgraph

You can just create your own custom flownodes and use them to trigger/receive UI functions/events. More information in the Creating a New Flow Node topic.

UI Event System

The UI System comes with an event system which can also used to communicate between C++ and the UI flowgraph.

The event system provides an easy way to define function and event nodes and handle them in C++.

Function nodes

Function nodes are available to all flowgraphs and provide an easy way to call C++ code.

Create a new .h file and name it UIFunctions.h

UIFunctions.h
#ifndef __UIFunctions_H__
#define __UIFunctions_H__

#include <IFlashUI.h>

class CUIFunctions : public IUIEventListener
{
public:
	CUIFunctions();
	~CUIFunctions();

	// IUIEventListener
	virtual void OnEvent( const SUIEvent& event );
	// ~IUIEventListener

private:
	SUIEventHelper<CUIFunctions> m_Dispatcher;
	IUIEventSystem* m_pGameEvents;

	void OnFoo( const SUIEvent& event );
	void OnBar( const SUIEvent& event );
};

#endif

Create a new .cpp file and name it UIFunctions.cpp

UIFunctions.cpp
#include "StdAfx.h"
#include "UIFunctions.h"

CUIFunctions::CUIFunctions()
	: m_pGameEvents(NULL)
{
	if (gEnv->pFlashUI)
	{
		// create a new event system called "Game"
		// type is eEST_UI_TO_SYSTEM; nodes for this event system will be found unter UI:Functions
		// register as event listener to the event system
		m_pGameEvents = gEnv->pFlashUI->CreateEventSystem( "Game", IUIEventSystem::eEST_UI_TO_SYSTEM );
		m_pGameEvents->RegisterListener( this );

		// create a new function description for "Foo"
		SUIEventDesc fooDesc( "Foo", "Foo", "Call a function named foo" );
		// add a parameter description "Arg1" to the function description
		fooDesc.Params.push_back( SUIParameterDesc( "Arg1", "Arg1", "First Arg" ) );
		// register the function description to the dispatcher
		m_Dispatcher.RegisterEvent( m_pGameEvents, fooDesc, &CUIFunctions::OnFoo );


		// create another function description for "Bar"
		SUIEventDesc barDesc( "Bar", "Bar", "Call a function named bar" );
		barDesc.Params.push_back( SUIParameterDesc( "Arg1", "Arg1", "First Arg" ) );
		barDesc.Params.push_back( SUIParameterDesc( "Arg2", "Arg2", "Second Arg" ) );
		m_Dispatcher.RegisterEvent( m_pGameEvents, barDesc, &CUIFunctions::OnBar );
	}
}

CUIFunctions::~CUIFunctions()
{
	if ( m_pGameEvents )
		m_pGameEvents->UnregisterListener( this );
}

void CUIFunctions::OnEvent( const SUIEvent& event )
{
	// use the dispatcher to dipatch the event to the correct function
	m_Dispatcher.Dispatch( this, event );
}

void CUIFunctions::OnFoo( const SUIEvent& event )
{
	int arg1 = 0;

	if ( !event.args.GetArg(0, arg1) )
	{
		CryLogAlways("Foo: argument 1 has wrong type (should be int)");
		return;
	}

	// do something
}

void CUIFunctions::OnBar( const SUIEvent& event )
{
	bool arg1 = false;
	float arg2 = 0;

	if ( !event.args.GetArg(0, arg1) )
	{
		CryLogAlways("Foo: argument 1 has wrong type (should be bool)");
		return;
	}

	if ( !event.args.GetArg(1, arg2) )
	{
		CryLogAlways("Foo: argument 2 has wrong type (should be float)");
		return;
	}

	// do something
}

Open Game.h, forward declare your class and add a private member to CGame:

Game.h
#ifndef __GAME_H__
#define __GAME_H__

...

class CUIFunctions;

...

class CGame :
  public IGame, public IGameFrameworkListener, public ILevelSystemListener
{
   ...

private:
   ...

CUIFunctions * m_pUIFunctions;

   ...
}

...

Open Game.cpp init m_pUIFunctions with NULL in the construcor, delete m_pUIFunctions in the deconstructor and create the CUIFunction object at the end of the init function.

Game.cpp
#include "StdAfx.h"
#include "Game.h"

...
#include "UIFunctions.h"

CGame::CGame()
   ...
{
    m_pUIFunctions = NULL;
}


CGame::~CGame()
{
   ...
   SAFE_DELETE(m_pUIFunctions);
}

...

bool CGame::Init(IGameFramework *pFramework)
{
   ...
   if (m_ pUIFunctions == NULL)
   {
      m_ pUIFunctions = new CUIFunctions();
   }
}
...

Note: It is important to create all your classes that uses the UI event system before CompleteInit is called.

This code will result in two new nodes UI:Functions:Game:Foo and UI:Functions:Game:Bar.

If the port "send" is triggered, it will call the C++ code in UIFunctions.cpp.

Event Nodes

Event nodes are very similar to Function nodes. They are used to send events from C++ to any UI flowgraph.
e.g. you can create a singleton class to call events from everywhere of your code.

Create a .h file UIGameEvents.h

UIGameEvents.h
#ifndef __UIGameEvents_H__
#define __UIGameEvents_H__

#include <IFlashUI.h>

class CUIGameEvents
{
public:
	// access to instance
	static CUIGameEvents* GetInstance()
	{
		static CUIGameEvents inst;
		return &inst;
	}

	// init the game events
	void Init();

	// events
	enum EUIGameEvents
	{
		eUIGE_FooEvent,
		eUIGE_BarEvent,
	};
	void SendEvent( EUIGameEvents event, const SUIArguments& args );

private:
	CUIGameEvents() : m_pGameEvents(NULL) {};
	~CUIGameEvents() {};

	IUIEventSystem* m_pGameEvents;
	std::map<EUIGameEvents, uint> m_EventMap;
};

#endif

Create a .cpp file UIGameEvents.cpp

UIGameEvents.cpp
#include "StdAfx.h"
#include "UIGameEvents.h"

void CUIGameEvents::Init()
{
	if (gEnv->pFlashUI)
	{
		// create a new event system called "Game"
		// type is eEST_SYSTEM_TO_UI; nodes for this event system will be found unter UI:Events
		m_pGameEvents = gEnv->pFlashUI->CreateEventSystem( "Game", IUIEventSystem::eEST_SYSTEM_TO_UI );

		// create a new event description for "Foo"
		SUIEventDesc fooDesc( "Foo", "Foo", "Event named foo" );
		// add a parameter description "Arg1" to the event description
		fooDesc.Params.push_back( SUIParameterDesc( "Arg1", "Arg1", "First Arg" ) );
		// register the event to the event system and associate the id with the event enum
		m_EventMap[ eUIGE_FooEvent ] = m_pGameEvents->RegisterEvent( fooDesc );

		// create another event description for "Bar"
		SUIEventDesc barDesc( "Bar", "Bar", "Event named bar" );
		barDesc.Params.push_back( SUIParameterDesc( "Arg1", "Arg1", "First Arg" ) );
		barDesc.Params.push_back( SUIParameterDesc( "Arg2", "Arg2", "Second Arg" ) );
		m_EventMap[ eUIGE_BarEvent ] = m_pGameEvents->RegisterEvent( barDesc );
	}
}

void CUIGameEvents::SendEvent( EUIGameEvents event, const SUIArguments& args )
{
	// send the event
	if (m_pGameEvents)
	{
		m_pGameEvents->SendEvent( SUIEvent(m_EventMap[event], args) );
	}
}

Open Game.cpp, include "UIGameEvents.h" and add to the end of the Init function:

Game.cpp
bool CGame::Init(IGameFramework *pFramework)
{
    ...
    CUIGameEvents::GetInstance()->Init();
}
...

The code will create two nodes for the flowgraph:

Now you can call from everywhere in your code the SendEvent function to trigger e.g. the UI:Events:Game:Bar Node:

int arg1 = 12;
float arg2 = 1.4f;

SUIArguments args;
args.AddArgument( arg1 );
args.AddArgument( arg2 );

CUIGameEvents::GetInstance()->SendEvent( CUIGameEvents::eUIGE_BarEvent, args );
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