Implementing the private instance methods

TextEditor has 49 private instance methods. Fortunately, many of the methods have only a few lines of code. Though you can implement them in any order, begin with getter and setter methods.

Private methods for category Getters & Setters

Method fileName

fileName

"Private - Answers the value of fileName."

^fileName.

Method fileName:

fileName: value

"Private - Sets the value of fileName."

fileName := value.

Method mainWindow

mainWindow

"Private - Answers the value for mainWindow."

^mainWindow.

Method modified

modified

"Private - Answers the value for modified."

^modified.

Method popup

popup

"Private - Answers the value for popup."

^popup.

Method shell

shell

"Private - Answers the value for shell."

^shell.

Method text

text

"Private - Answers the receiver's text widget."

^text.

Method workRegion:

workRegion: aWidget

"Private - Sets the work region to aWidget."

workRegion := aWidget.

Private methods for category Initialization & Startup

Method initialize

initialize

"Private - Initializes the receiver."

modified := false. "Text has not changed since last save."

Private methods for category Window Creation

Method createWindow

createWindow

"Private - Creates a window for the text editor."

self

createMainWindow;

createMenuBar;

createWorkRegion;

createPulldownMenus.

self createTopLevelShell.

self createPopupMenu.

self addPopupMenu.

Method createMainWindow

createMainWindow

"Private - Creates a window."

mainWindow :=

CwMainWindow

createWidget: 'mainWindow'

parent: self shell

argBlock: nil.

Method createTopLevelShell

createTopLevelShell

"Private - Creates a form to hold user interface elements."

self shell width: 600; height: 400.

self shell

addCallback: XmNwindowCloseCallback

receiver: self

selector: #windowClose:clientData:callData:

clientData: nil.

Method createShell

createShell

"Private - Create a shell for aWidget."

shell :=

CwTopLevelShell

appCreateShell: self class name

applicationClass: CwAppContext defaultApplicationClass

display: CgDisplay default

argBlock: nil.

Method createMenuBar

createMenuBar

"Private - Creates a menu bar for the window."

menuBar :=

(mainWindow

createMenuBar: 'menuBar'

argBlock: nil) manageChild.

Method createWorkRegion

createWorkRegion

"Private - Creates a work region."

(text := self mainWindow createScrolledText: 'text' argBlock: [:w | w

editMode: XmMULTILINEEDIT])

manageChild.

self workRegion: self text parent.

self addValueChangedCallback.

Method createPulldownMenus

createPulldownMenus

"Private - Creates pulldown menus."

self createFileMenu.

self createEditMenuForTextWidget: self text.

Method addPulldownMenu:

addPulldownMenu: label

"Private - Adds a pulldown menu to the menu bar."

^self addMenuTo: menuBar label: label

Method addMenuTo:label:

addMenuTo: aParent label: labelString

"Private - Adds a menu."

| rowColumn labelButton |

rowColumn := aParent

createPulldownMenu: 'RowColumn',labelString

argBlock: nil.

labelButton := aParent

createCascadeButton: labelString

argBlock: nil.

labelButton

subMenuId: rowColumn;

manageChild.

^labelButton.

Method addMenuEntryTo:label:selector:

addMenuEntryTo: aParent label: aLabel selector: aSelector

"Private - Adds a menu choice to a menu."

^self

addMenuEntryTo: aParent

label: aLabel

selector: aSelector

clientData: nil.

Method addMenuEntryTo:label:selector:clientData:

addMenuEntryTo: aParent label: aLabel selector: aSelector clientData: clientData

"Private - Creates a push button with name aLabel, parent aParent,

callback aSelector, and nil as the client data for the callback.

Manages the resulting widget."

| aButton |

aButton := CwPushButton

createManagedWidget: aLabel

parent: aParent

argBlock: nil.

aButton

addCallback: XmNactivateCallback

receiver: self

selector: aSelector

clientData: clientData;

labelString: aLabel.

^aButton.

Method createEditMenuForTextWidget:

createEditMenuForTextWidget: aTextWidget

"Private - Creates an Edit menu."

| aMenu |

aMenu := (self addMenuTo: menuBar label: 'Edit') subMenuId.

self addMenuEntryTo: aMenu

label: 'Copy'

selector: #copySelection:clientData:callData:

clientData: aTextWidget.

self addMenuEntryTo: aMenu

label: 'Cut'

selector: #cutSelection:clientData:callData:

clientData: aTextWidget.

self addMenuEntryTo: aMenu

label: 'Paste'

selector: #pasteSelection:clientData:callData:

clientData: aTextWidget.

^aMenu.

Method createFileMenu

createFileMenu

"Private - Creates a File menu. Answers the pulldown menu."

| fileMenu |

fileMenu := (self addPulldownMenu: 'File') subMenuId.

(self

addMenuEntryTo: fileMenu

label: 'New Workspace'

selector: #newWorkspace:clientData:callData:)

accelerator: (CwAccelerator mask: ControlMask keysym: XKn);

acceleratorText: 'Ctrl+N'.

(self

addMenuEntryTo: fileMenu

label: 'Open...'

selector: #open:clientData:callData:)

accelerator: (CwAccelerator mask: ControlMask keysym: XKo);

acceleratorText: 'Ctrl+O'.

(fileMenu

createSeparator: '-' argBlock: nil)

manageChild.

(self

addMenuEntryTo: fileMenu

label: 'Save' selector: #accept:clientData:callData:)

accelerator: (CwAccelerator mask: ControlMask keysym: XKs);

acceleratorText: 'Ctrl+S'.

self addMenuEntryTo: fileMenu label: 'Save As...'

selector: #saveAs:clientData:callData:.

(self

addMenuEntryTo: fileMenu

label: 'Undo'

selector: #undo:clientData:callData:)

accelerator: (CwAccelerator mask: ControlMask keysym: XKr);

acceleratorText: 'Ctrl+R'.

(fileMenu

createSeparator: '-' argBlock: nil)

manageChild.

(self

addMenuEntryTo: fileMenu

label: 'Exit'

selector: #windowClose:clientData:callData:)

accelerator: (CwAccelerator mask: ControlMask keysym: XKq);

acceleratorText: 'Ctrl+Q'.

^fileMenu.

Method createPopupMenu

createPopupMenu

"Private - Calls methods which define choices in the popup menu."

| clientData |

popup := self text

createPopupMenu: 'popup'

argBlock: nil.

clientData := Array with: self text with: [self].

self createPopupUndo.

self createPopupCopy.

self createPopupCut.

self createPopupPaste.

self createPopupSave.

Method addPopupMenu

addPopupMenu

"Private - Creates a popup menu."

self text

addEventHandler: ButtonMenuMask

receiver: self

selector: #popup:clientData:callData:

clientData: self popup.

Method createPopupCopy

createPopupCopy

"Private - Creates a Copy menu choice."

| button |

button := popup createPushButton: 'Copy' argBlock: nil.

button

addCallback: XmNactivateCallback

receiver: self

selector: #copySelection:clientData:callData:

clientData: self text;

manageChild.

Method createPopupCut

createPopupCut

"Private - Creates a Cut menu choice."

| button |

button := popup createPushButton: 'Cut' argBlock: nil.

button

addCallback: XmNactivateCallback

receiver: self

selector: #cutSelection:clientData:callData:

clientData: self text;

manageChild.

Method createPopupPaste

createPopupPaste

"Private - Creates a Paste menu choice."

| button |

button := popup createPushButton: 'Paste' argBlock: nil.

button

addCallback: XmNactivateCallback

receiver: self

selector: #pasteSelection:clientData:callData:

clientData: self text;

manageChild.

(popup

createSeparator: '-' argBlock: nil)

manageChild.

Method createPopupSave

createPopupSave

"Private - Creates a Save menu choice."

| button |

button := popup createPushButton: 'Save' argBlock: nil.

button

addCallback: XmNactivateCallback

receiver: self

selector: #accept:clientData:callData:

clientData: self text;

manageChild.

Method createPopupUndo

createPopupUndo

"Private - Creates an Undo menu choice."

| button |

button := popup createPushButton: 'Undo' argBlock: nil.

button

addCallback: XmNactivateCallback

receiver: self

selector: #undo:clientData:callData:

clientData: self text;

manageChild.

(popup

createSeparator: '-' argBlock: nil)

manageChild.

Method realizeWindow

realizeWindow

"Private - Realizes the receiver's widget hierarchy."

shell realizeWidget.

Private methods for category Event Handlers

Method accept:clientData:callData:

accept: w clientData: clientData callData: callData

"Private - Calls methods that save the text."

fileName isNil

ifTrue: [self saveAs: w clientData: clientData callData: callData]

ifFalse: [

self

writeFileName: fileName;

removeValueChangedCallback;

addValueChangedCallback].

Method addValueChangedCallback

addValueChangedCallback

"Private - Adds the valueChangedCallback and clears the modified flag."

self text

addCallback: XmNvalueChangedCallback

receiver: self

selector: #valueChanged:clientData:callData:

clientData: nil.

modified := false.

Method copySelection:clientData:callData:

copySelection: aButton clientData: aTextWidget callData: callData

"Private - Marks selected text for copying."

^aTextWidget copySelection

Method cutSelection:clientData:callData:

cutSelection: aButton clientData: aTextWidget callData: callData

"Private - Marks selected text for cut operation."

^aTextWidget cutSelection

Method newWorkspace:clientData:callData:

newWorkspace: w clientData: ignore1 callData: ignore2

"Private - Opens a second instance of the text editor."

self class new open.

Method open:clientData:callData:

open: w clientData: ignored1 callData: ignored2

"Private - Processes the open callback from the file menu."

| name |

(name :=

(CwFileSelectionPrompter for: self shell)

title: 'Open File';

prompt) isNil

ifTrue: [^self].

self removeValueChangedCallback.

self readFileName: name.

self addValueChangedCallback.

self updateTitle.

Method pasteSelection:clientData:callData:

pasteSelection: aButton clientData: aTextWidget callData: callData

"Private - Pastes text in the clipboard."

^aTextWidget paste.

Method popup:clientData:callData:

popup: label clientData: aMenu callData: event

"Private - Pops up a menu under the cursor."

event button = 3 ifFalse: [^self].

aMenu

menuPosition: event;

manageChild.

Method removeValueChangedCallback

removeValueChangedCallback

"Private - Removes the valueChangedCallback."

self text

removeCallback: XmNvalueChangedCallback

receiver: self

selector: #valueChanged:clientData:callData:

clientData: nil.

Method saveAs:clientData:callData:

saveAs: w clientData: clientData callData: callData

"Private - Processes the saveAs callback from the file menu."

| name |

(name :=

(CwFileSelectionPrompter for: self shell)

title: 'Save As';

prompt) isNil

ifTrue: [^self].

self writeFileName: name.

self

removeValueChangedCallback;

addValueChangedCallback.

self updateTitle.

Method undo:clientData:callData:

undo: widget clientData: clientData callData: callData

"Private - Processes the undo callback from the file menu. Re-reads the

contents of the last opened or saved file into the workspace."

self removeValueChangedCallback.

fileName isNil

ifTrue: [self text setString: '']

ifFalse: [

self readFileName: fileName].

self addValueChangedCallback.

Method updateTitle

updateTitle

"Private - Updates the window title."

(fileName isNil or: [fileName = ''])

ifTrue: [^self shell title: self class printString].

self shell title: fileName.

Method valueChanged:clientData:callData:

valueChanged: w clientData: ignore1 callData: ignore2

"Private - Processes the valueChangedCallback from the text widget.

Sets the modified flag to true and removes the callback."

modified := true.

self removeValueChangedCallback.

Method windowClose:clientData:callData:

windowClose: w clientData: clientData callData: callData

"Private - Process the exit callback from the file menu. If the text

has changed since the last save, prompt for the Save As dialog."

self modified

ifTrue: [

((CwMessagePrompter for: self shell)

iconType: XmICONQUESTION;

buttonType: XmYESNO;

messageString: 'Text has been modified - discard changes?';

prompt) = true

ifFalse: [self saveAs: w clientData: clientData callData: callData].

].

self shell unmapWidget.

Private methods for category File Operations

Method readFileName:

readFileName: name

"Private - Reads the contents of the specified file into the workspace."

| size file string result |

file := CfsFileDescriptor open: name oflag: ORDONLY.

file isCfsError

ifTrue: [

^(CwMessagePrompter for: self shell)

iconType: XmICONERROR;

messageString: file printString;

prompt

].

(size := file size) >= self text maxLength

ifTrue: [

file close.

^(CwMessagePrompter for: self shell)

iconType: XmICONERROR;

messageString: 'File size (',size printString,') is greater

than Text widget maxLength (',

self text maxLength printString,')' ;

prompt

].

self showFontCursor: XCWatch in: self shell window while: [

string := String new: file size.

result := file read: string startingAt: 1 nbyte: file size.

].

result isCfsError

ifTrue: [

file close.

^(CwMessagePrompter for: self shell)

iconType: XmICONERROR;

messageString: result printString;

prompt

].

self showFontCursor: XCWatch in: self shell window while: [

self text setString: string.

].

fileName := name.

file close.

Method showCursor:in:while:

showCursor: cursor in: aCgWindow while: aBlock

"Private - shows cursor."

| result |

aCgWindow defineCursor: cursor.

result := aBlock value.

aCgWindow undefineCursor.

^result.

Method showFontCursor:in:while:

showFontCursor: anInteger in: aCgWindow while: aBlock

"Private - Shows cursor."

| cursor |

cursor := self display createFontCursor: anInteger.

self showCursor: cursor in: aCgWindow while: aBlock.

cursor freeCursor.

Method writeFileName:

writeFileName: name

"Private - Writes the contents of the workspace to the specified file."

| file string result |

file := CfsFileDescriptor open: name oflag: OCREAT | OTRUNC | OWRONLY.

file isCfsError

ifTrue: [

^(CwMessagePrompter for: self shell)

iconType: XmICONERROR;

messageString: file printString;

prompt

].

self showFontCursor: XCWatch in: self shell window while: [

string := self text getString.

result := file write: string startingAt: 1 nbyte: string size.

].

result isCfsError

ifTrue: [

file close.

^(CwMessagePrompter for: self shell)

iconType: XmICONERROR;

messageString: result printString;

prompt

].

fileName := name.

file close.

Now that you have all of the methods implemented for TextEditor, try opening an instance of the class using DevelopChooser or by evaluating:

TextEditor new open.

The finished window resembles the following: