Represents a rectangular region that can handle messages directed to that region. More...

Inheritance diagram for MessageWindow:

Collaboration diagram for MessageWindow:

Public Member Functions
bool	ProcessMessage (Message message)
	Processes a message.

override string	ToString ()
	Convert this handler to a string.

bool	ProcessMessage (Message message)
	Called with a message on each window.

string	ToString ()
	Convert the handler to a string.

Static Public Member Functions
static MessageWindow	CreateWindow (string title, int x, int y, int width, int height, HandlerChain handlerChain)
	Creates an instance of the MessageWindow class with the specified attributes and adds the new instance to the given HandlerChain object.

Properties
int	ID `[get]`
	Returns the ID of the message handler.

Properties inherited from IMessageHandler
int	ID `[get]`
	ID of the window. This is used to uniquely identify a window in the collection.

Private Member Functions
delegate bool	MessageHandler (Message message)

bool	_PointInWindow (MessagePosition position)
	Determine if the specified point is in this MessageWindow's region.

bool	_PointInCloseBox (MessagePosition position)
	Determine if the specified point is in this MessageWindow's "close" region.

	MessageWindow (int windowId, string title, int x, int y, int width, int height, HandlerChain handlerChain)
	Constructor.

bool	_HandleButtonDownMessage (Message message)
	Helper method to handle the ButtonDown message.

bool	_HandleButtonUpMessage (Message message)
	Helper method to handle the ButtonUp message.

bool	_HandleCloseMessage (Message message)
	Helper method to handle the Close message.

Private Attributes
Dictionary< MessageType, MessageHandler >	_messageHandlers = new Dictionary<MessageType, MessageHandler>()
	Maps a message type to a handler method of type MessageHandler.

int	_windowId
	Unique ID of this window.

string	_title
	Title/Name of this window.

WindowRectangle	_windowBox
	Position of this window in global coordinates.

WindowRectangle	_closeBox
	Position of the close window within the window box, although the coordinates are also global coordinates to eliminate the need to convert between window and global coordinates.

bool	_selected
	Whether this window has been selected (a button click occurred within the window).

HandlerChain	_handlerChain
	The HandlerChain to which this window belongs (as an IMessageHandler object).

Static Private Attributes
const int	CLOSE_WIDTH = 2

const int	CLOSE_HEIGHT = 2

static int	_nextWindowId = 1
	Used for assigning a unique ID to each created window.

Detailed Description

Represents a rectangular region that can handle messages directed to that region.

Note: The IMessageHandler interface is an example of a Facade design pattern, where the complexity of the MessageWindow is exposed only through a few methods to a system that only needs to deal with those few methods.

Definition at line 97 of file HandlerChain_MessageWindow_Class.cs.

Constructor & Destructor Documentation

◆ MessageWindow()

MessageWindow	(	int	windowId,
		string	title,
		int	x,
		int	y,
		int	width,
		int	height,
		HandlerChain	handlerChain
	)

inlineprivate

Constructor.

Parameters

windowId	Unique ID of the window to use.
title	Title of the window.
x	Global x position of the upper left corner of the window's region.
y	Global y position of the upper left corner of the window's region.
width	Width of the window's region.
height	Height of the window's region.
handlerChain	A HandlerChain object that will be used for removal of this window when it is closed.

Definition at line 211 of file HandlerChain_MessageWindow_Class.cs.

References MessageWindow._closeBox, MessageWindow._HandleButtonDownMessage(), MessageWindow._HandleButtonUpMessage(), MessageWindow._HandleCloseMessage(), MessageWindow._handlerChain, MessageWindow._messageHandlers, MessageWindow._selected, MessageWindow._title, MessageWindow._windowBox, MessageWindow._windowId, MessageWindow.CLOSE_HEIGHT, MessageWindow.CLOSE_WIDTH, WindowRectangle.Right, and WindowRectangle.Top.

Member Function Documentation

◆ _HandleButtonDownMessage()

bool _HandleButtonDownMessage ( Message message )

inlineprivate

Helper method to handle the ButtonDown message.

Parameters

message A Message object describing the ButtonDown message.

Returns: Always returns false even if the message was handled (allows other windows to select/deselect themselves).

Definition at line 242 of file HandlerChain_MessageWindow_Class.cs.

References MessageWindow._PointInWindow(), MessageWindow._selected, MessageWindow._title, and Message.Position.

Referenced by MessageWindow.MessageWindow().

◆ _HandleButtonUpMessage()

bool _HandleButtonUpMessage ( Message message )

inlineprivate

Helper method to handle the ButtonUp message.

Parameters

message A Message object describing the ButtonUp message.

Returns: Returns true if the message was handled; otherwise, returns false indicating the message was not handled.

Definition at line 275 of file HandlerChain_MessageWindow_Class.cs.

References MessageWindow._handlerChain, MessageWindow._PointInCloseBox(), MessageWindow._PointInWindow(), MessageWindow._selected, MessageWindow._title, Message.Position, and HandlerChain.SendMessage().

Referenced by MessageWindow.MessageWindow().

◆ _HandleCloseMessage()

bool _HandleCloseMessage ( Message message )

inlineprivate

Helper method to handle the Close message.

Parameters

message A Message object describing the Close message.

Returns: Returns true if the message was handled; otherwise, returns false indicating the message was not handled.

Definition at line 307 of file HandlerChain_MessageWindow_Class.cs.

References MessageWindow._handlerChain, MessageWindow._selected, MessageWindow._title, and HandlerChain.RemoveHandler().

Referenced by MessageWindow.MessageWindow().

◆ _PointInCloseBox()

bool _PointInCloseBox ( MessagePosition position )

inlineprivate

Determine if the specified point is in this MessageWindow's "close" region.

Parameters

position The point to examine.

Returns: Returns true if the point is contained within the MessageWindow's "close" region.

Definition at line 193 of file HandlerChain_MessageWindow_Class.cs.

References MessageWindow._closeBox, and WindowRectangle.PointInside().

Referenced by MessageWindow._HandleButtonUpMessage().

◆ _PointInWindow()

bool _PointInWindow ( MessagePosition position )

inlineprivate

Determine if the specified point is in this MessageWindow's region.

Parameters

position The global coordinate to examine.

Returns: Returns true if the point is contained within the MessageWindow's region.

Definition at line 180 of file HandlerChain_MessageWindow_Class.cs.

References MessageWindow._windowBox, and WindowRectangle.PointInside().

Referenced by MessageWindow._HandleButtonDownMessage(), and MessageWindow._HandleButtonUpMessage().

◆ CreateWindow()

static MessageWindow CreateWindow	(	string	title,
		int	x,
		int	y,
		int	width,
		int	height,
		HandlerChain	handlerChain
	)

inlinestatic

Creates an instance of the MessageWindow class with the specified attributes and adds the new instance to the given HandlerChain object.

Parameters

title	Title of the MessageWindow.
x	X position of the upper left corner of the window's region.
y	Y position of the upper left corner of hte window's region.
width	Width of the window's region.
height	Height of the window's region.
handlerChain	A HandlerChain object that will be given the window.

Returns: Returns the newly created MessageWindow.

Each MessageWindow instance is assigned a unique ID, which is required by the HandlerChain object.

Definition at line 165 of file HandlerChain_MessageWindow_Class.cs.

References MessageWindow._nextWindowId, and HandlerChain.AddHandler().

Referenced by HandlerChain_Exercise._HandlerChain_ConstructWindowChain().

◆ MessageHandler()

delegate bool MessageHandler ( Message message )

private

Referenced by MessageWindow.ProcessMessage().

◆ ProcessMessage()

bool ProcessMessage ( Message message )

inline

Processes a message.

Parameters

message The Message object to process.

Returns: Returns true if the message was handled and no further windows should be notified; otherwise return false to allow the message to be passed to subsequent windows.

The message types are mapped to handlers in the MessageWindow constructor and stored in the _messageHandlers dictionary.

Implements IMessageHandler.

Definition at line 354 of file HandlerChain_MessageWindow_Class.cs.

References MessageWindow._messageHandlers, MessageWindow.MessageHandler(), and Message.MessageType.

◆ ToString()

override string ToString ( )

inline

Convert this handler to a string.

Returns: Returns a string representation of the message handler.

Implements IMessageHandler.

Definition at line 372 of file HandlerChain_MessageWindow_Class.cs.

References MessageWindow._selected, MessageWindow._title, MessageWindow._windowBox, and MessageWindow.ID.

Member Data Documentation

◆ _closeBox

WindowRectangle _closeBox

private

Position of the close window within the window box, although the coordinates are also global coordinates to eliminate the need to convert between window and global coordinates.

Definition at line 130 of file HandlerChain_MessageWindow_Class.cs.

Referenced by MessageWindow._PointInCloseBox(), and MessageWindow.MessageWindow().