Friday, October 28, 2011

Creating a Flex AIR text editor: Part 18

In this tutorial we will do two things - firstly we will make it so that each untitled tab gets numbered, so that there won't be two same tabs. The second thing we're going to do is ask for confirmation for each unsaved tab's closing when the user tries to close the main application.

Firstly, declare a new variable untitledNum, which will be the number that we will be increasing and adding to the title of each new tab:

private var untitledNum:int = 0;

In the doNew() function, add a line that adds 1 to the untitledNum variable and then add this variable to the title value:

private function doNew():void {
statusMessage = "[ " + new Date().toLocaleTimeString() + " ] New tab created";
updateStatus();
untitledNum++;
tabData.addItem( { title:"Untitled("+untitledNum+")", textData:"", saved:false } );
tabBar.selectedIndex = tabData.length - 1;
tabChange();
}

Now, for the closing part.

When the user closes the main window and has unsaved tabs opened, the default behavior of the closing functionality should be prevented and instead of that, the application should ask confirmation about each unsaved tab. When the last confirmation is completed, we can close the window safely.

How do we find out which tab is the last, and when do we actually close the window? We can keep track of all the tabs by creating a variable which holds a number of unsaved tabs that need to be closed. As the user confirms each tab, 1 is substracted from that variable. Then, in the confirmation function, if this variable equals 0, this means that this was the last tab and we should close now. We can make sure when to close the window by creating a boolean variable closeAfterConfirm. If it is true and tabsToClose equals 0, we can close the window.

Now, let's code this.

Declare the two variables I mentioned:

private var tabsToClose:int = 0;
private var closeAfterConfirm:Boolean = false;

Update the onClose function by adding a loop to check if there are unsaved tabs and a loop to use closeTab() on all tabs if there are unsaved ones. If we don't need to save, close the window.

private function onClose(evt:Event):void {
if(!closeAfterConfirm){
evt.preventDefault();
var allWindows:Array = NativeApplication.nativeApplication.openedWindows;
for (var i:int = 1; i < allWindows.length; i++)
{
allWindows[i].close();
}

// Check if there are any unsaved tabs
var needSaving:Boolean = false;
tabsToClose = 0;

for (var u:int = 0; u < tabData.length; u++) {
if (tabData[u].saved == false) {
needSaving = true;
tabsToClose++;
}
}

// If there are unsaved tabs, dont close window yet, set closeAfterConfirm to true and close all tabs
if (needSaving) {
closeAfterConfirm = true;
for (var t:int = 0; t < tabData.length; t++) {
closeTab(t);
}
}
if (!needSaving) {
FlexGlobals.topLevelApplication.close();
}
}
}

The closeTab function needs to be updated too. We need to remember to substract 1 from tabsToClose on confirmation, and we need to call removeTab() when the user pressed Yes or No. Later we will add a saving function to be called when the user presses Yes.

private function closeTab(index:int):void {
if (tabData[index].saved) {
removeTab(index);
}
if (!tabData[index].saved) {
Alert.show("Save " + tabData[index].title + " before closing?", "Confirmation", Alert.YES | Alert.NO, null, confirmClose);
}
function confirmClose(evt:CloseEvent):void {
tabsToClose--;
if (evt.detail == Alert.YES) {
// TODO: call saving function here
removeTab(index);
}else {
removeTab(index);
}
}
}

Finally, we update the removeTab function by creating a conditional that closes the main window if closeAfterConfirm is set to true and tabsToClose equals 0.

private function removeTab(index:int):void {
// if this is the last tab, create a new empty tab
if (tabData.length == 1) {
tabData.addItem( { title:"Untitled", textData:"", saved:false } );
}
statusMessage = "[ " + new Date().toLocaleTimeString() + " ] Tab closed: " + tabData[index].title;
updateStatus();
tabData.removeItemAt(index);
previousIndex = tabBar.selectedIndex;
textArea.text = tabData[tabBar.selectedIndex].textData;
textArea.selectRange(tabData[tabBar.selectedIndex].selectedAnchor, tabData[tabBar.selectedIndex].selectedActive);
if (closeAfterConfirm && tabsToClose == 0) {
FlexGlobals.topLevelApplication.close();
}
}

And that's all!

Full code:

<?xml version="1.0" encoding="utf-8"?>
<s:WindowedApplication xmlns:fx="http://ns.adobe.com/mxml/2009"
                       xmlns:s="library://ns.adobe.com/flex/spark"
                       xmlns:mx="library://ns.adobe.com/flex/mx"
   xmlns:custom="*"
   creationComplete="init();" title="Kirpad" showStatusBar="{pref_status}">
   
<s:menu>
<mx:FlexNativeMenu dataProvider="{windowMenu}" showRoot="false" labelField="@label" keyEquivalentField="@key" itemClick="menuSelect(event);" />
</s:menu>

<fx:Script>
<![CDATA[
import flash.events.KeyboardEvent;
import flash.events.Event;
import flash.events.MouseEvent;
import flash.events.NativeWindowBoundsEvent;
import flash.net.SharedObject;
import mx.collections.ArrayCollection;
import mx.controls.Alert;
import mx.events.FlexNativeMenuEvent;
import flashx.textLayout.elements.TextFlow;
import flashx.textLayout.elements.Configuration;
import flash.system.System;
import flash.desktop.Clipboard;
import flash.desktop.ClipboardFormats;
import flash.ui.Mouse;
import mx.events.CloseEvent;
import flash.ui.ContextMenu;
import flash.ui.ContextMenuItem;
import flash.events.ContextMenuEvent;
import mx.events.ResizeEvent;
import mx.core.FlexGlobals;

private var preferences:SharedObject = SharedObject.getLocal("kirpadPreferences");
[Bindable]
private var pref_wrap:Boolean = true;
[Bindable]
private var pref_status:Boolean = true;
[Bindable]
private var pref_toolbar:Boolean = true;
[Bindable]
public var pref_fontsettings:Object = new Object();

private var initHeight:Number;
private var heightFixed:Boolean = false;

private var statusMessage:String;
[Bindable]
private var textHeight:Number;
[Bindable]
private var textY:Number;
[Bindable]
private var tabY:Number;

private var previousIndex:int = 0;
private var rightclickTabIndex:int = 0;
private var untitledNum:int = 0;
private var tabsToClose:int = 0;
private var closeAfterConfirm:Boolean = false;

public var fontWindow:FontWindow = new FontWindow();

private function init():void {

// Create a listener for every frame
addEventListener(Event.ENTER_FRAME, everyFrame);

// Set initHeight to the initial height value on start
initHeight = height;

// Set preferences if loaded for the first time
if (preferences.data.firsttime == null) {
preferences.data.firsttime = true;
preferences.data.wrap = true;
preferences.data.status = true;
preferences.data.toolbar = true;
preferences.data.fontsettings = {fontfamily:"Lucida Console", fontsize:14, fontstyle:"normal", fontweight:"normal", fontcolor:0x000000, bgcolor:0xffffff};
preferences.flush();
}

// Set preferences loaded from local storage
pref_wrap = preferences.data.wrap;
pref_status = preferences.data.status;
pref_toolbar = preferences.data.toolbar;
pref_fontsettings = preferences.data.fontsettings;

// Allow insertion of tabs
var textFlow:TextFlow = textArea.textFlow;
var config:Configuration = Configuration(textFlow.configuration);
config.manageTabKey = true;

// Set status message
statusMessage = "[ " + new Date().toLocaleTimeString() + " ] Kirpad initialized";
updateStatus();

// Close all sub-windows if main window is closed
addEventListener(Event.CLOSING, onClose);

// Add listener for the event that is dispatched when new font settings are applied
fontWindow.addEventListener(Event.CHANGE, fontChange);

// Update real fonts with the data from the settings values
updateFonts();

// Create a listener for resizing
addEventListener(NativeWindowBoundsEvent.RESIZE, onResize);

// Context menu declaration for the tabbar control
var cm_close:ContextMenuItem = new ContextMenuItem("Close tab");
cm_close.addEventListener(ContextMenuEvent.MENU_ITEM_SELECT, tabContextClose);
var cm_closeother:ContextMenuItem = new ContextMenuItem("Close other tabs");
cm_closeother.addEventListener(ContextMenuEvent.MENU_ITEM_SELECT, tabContextCloseOther);

var cm:ContextMenu = new ContextMenu();
cm.items = [cm_close, cm_closeother];
cm.hideBuiltInItems();
tabBar.contextMenu = cm;
tabBar.addEventListener(MouseEvent.RIGHT_MOUSE_DOWN, tabRightClick);

// Listen to keyboard
addEventListener(KeyboardEvent.KEY_DOWN, onKeyDown);
}

private function menuSelect(evt:FlexNativeMenuEvent):void {
(evt.item.@label == "New")?(doNew()):(void);
(evt.item.@label == "Word wrap")?(pref_wrap = !pref_wrap):(void);
(evt.item.@label == "Cut")?(doCut()):(void);
(evt.item.@label == "Copy")?(doCopy()):(void);
(evt.item.@label == "Paste")?(doPaste()):(void);
(evt.item.@label == "Select all")?(doSelectall()):(void);
(evt.item.@label == "Status bar")?(pref_status = !pref_status):(void);
(evt.item.@label == "Tool bar")?(pref_toolbar = !pref_toolbar):(void);
(evt.item.@label == "Font...")?(doFont()):(void);
savePreferences();
updateStatus();
}

private function savePreferences():void {
preferences.data.wrap = pref_wrap;
preferences.data.status = pref_status;
preferences.data.toolbar = pref_toolbar;
preferences.data.fontsettings = pref_fontsettings;
preferences.flush();
}

private function doCut():void {
var selectedText:String = textArea.text.substring(textArea.selectionActivePosition, textArea.selectionAnchorPosition);
System.setClipboard(selectedText);
insertText("");
}

private function doCopy():void {
var selectedText:String = textArea.text.substring(textArea.selectionActivePosition, textArea.selectionAnchorPosition);
System.setClipboard(selectedText);
}

private function doPaste():void{
var myClip:Clipboard = Clipboard.generalClipboard;
var pastedText:String = myClip.getData(ClipboardFormats.TEXT_FORMAT) as String;
insertText(pastedText);
}

private function doSelectall():void {
textArea.selectAll();
}

private function insertText(str:String):void {
var substrPositions:int = textArea.selectionActivePosition - textArea.selectionAnchorPosition;
var oldSel1:int = (substrPositions>0)?(textArea.selectionAnchorPosition):(textArea.selectionActivePosition);
var oldSel2:int = (substrPositions<0)?(textArea.selectionAnchorPosition):(textArea.selectionActivePosition);
var preText:String = textArea.text.substring(0, oldSel1);
var postText:String = textArea.text.substring(oldSel2);
var newSelectRange:int = preText.length + str.length;
textArea.text = preText + str + postText;
textArea.selectRange(newSelectRange, newSelectRange);
}

private function cursorFix():void{
Mouse.cursor = "ibeam";
}

private function everyFrame(evt:Event):void {
if (!heightFixed && height==initHeight) {
height = initHeight - 20;
if (height != initHeight) {
heightFixed = true;
updateTextSize();
}
}
}

private function onResize(evt:ResizeEvent):void {
updateTextSize();
}

private function updateTextSize():void {
tabY = (toolBar.visible)?(toolBar.height):(0);
textY = tabBar.height + tabY;
var statusHeight:Number = (pref_status)?(statusBar.height):(0);
textHeight = height - textY - statusHeight;
focusManager.setFocus(textArea);
}

private function updateStatus():void {
var str:String = new String();
str = (pref_wrap)?("Word wrapping on"):(caretPosition());
status = str + "\t" + statusMessage;
}

private function caretPosition():String {
var pos:int = textArea.selectionActivePosition;
var str:String = textArea.text.substring(0, pos);
var lines:Array = str.split("\n");
var line:int = lines.length;
var col:int = lines[lines.length - 1].length + 1;

return "Ln " + line + ", Col " + col;
}

private function doFont():void{
fontWindow.open();
fontWindow.activate();
fontWindow.visible = true;
fontWindow.setValues(pref_fontsettings.fontsize, pref_fontsettings.fontfamily, pref_fontsettings.fontstyle, pref_fontsettings.fontweight, pref_fontsettings.fontcolor, pref_fontsettings.bgcolor);
}

private function onClose(evt:Event):void {
if(!closeAfterConfirm){
evt.preventDefault();
var allWindows:Array = NativeApplication.nativeApplication.openedWindows;
for (var i:int = 1; i < allWindows.length; i++)
{
allWindows[i].close();
}

// Check if there are any unsaved tabs
var needSaving:Boolean = false;
tabsToClose = 0;

for (var u:int = 0; u < tabData.length; u++) {
if (tabData[u].saved == false) {
needSaving = true;
tabsToClose++;
}
}

// If there are unsaved tabs, dont close window yet, set closeAfterConfirm to true and close all tabs
if (needSaving) {
closeAfterConfirm = true;
for (var t:int = 0; t < tabData.length; t++) {
closeTab(t);
}
}
if (!needSaving) {
FlexGlobals.topLevelApplication.close();
}
}
}

private function fontChange(evt:Event):void{
pref_fontsettings.fontfamily = fontWindow.fontCombo.selectedItem.fontName;
pref_fontsettings.fontsize = fontWindow.sizeStepper.value;

if (fontWindow.styleCombo.selectedIndex == 0) {
pref_fontsettings.fontstyle = "normal";
pref_fontsettings.fontweight = "normal";
}
if (fontWindow.styleCombo.selectedIndex == 1) {
pref_fontsettings.fontstyle = "italic";
pref_fontsettings.fontweight = "normal";
}
if (fontWindow.styleCombo.selectedIndex == 2) {
pref_fontsettings.fontstyle = "normal";
pref_fontsettings.fontweight = "bold";
}
if (fontWindow.styleCombo.selectedIndex == 3) {
pref_fontsettings.fontstyle = "italic";
pref_fontsettings.fontweight = "bold";
}

pref_fontsettings.fontcolor = fontWindow.colorPicker.selectedColor;
pref_fontsettings.bgcolor = fontWindow.bgColorPicker.selectedColor;

savePreferences();
updateFonts();
}

private function updateFonts():void{
textArea.setStyle("fontFamily", pref_fontsettings.fontfamily);
textArea.setStyle("fontSize", pref_fontsettings.fontsize);
textArea.setStyle("fontStyle", pref_fontsettings.fontstyle);
textArea.setStyle("fontWeight", pref_fontsettings.fontweight);
textArea.setStyle("color", pref_fontsettings.fontcolor);
textArea.setStyle("contentBackgroundColor", pref_fontsettings.bgcolor);
}

private function onTabClose(evt:Event):void {
closeTab(tabBar.selectedIndex);
}

private function closeTab(index:int):void {
if (tabData[index].saved) {
removeTab(index);
}
if (!tabData[index].saved) {
Alert.show("Save " + tabData[index].title + " before closing?", "Confirmation", Alert.YES | Alert.NO, null, confirmClose);
}
function confirmClose(evt:CloseEvent):void {
tabsToClose--;
if (evt.detail == Alert.YES) {
// TODO: call saving function here
removeTab(index);
}else {
removeTab(index);
}
}
}

private function removeTab(index:int):void {
// if this is the last tab, create a new empty tab
if (tabData.length == 1) {
tabData.addItem( { title:"Untitled", textData:"", saved:false } );
}
statusMessage = "[ " + new Date().toLocaleTimeString() + " ] Tab closed: " + tabData[index].title;
updateStatus();
tabData.removeItemAt(index);
previousIndex = tabBar.selectedIndex;
textArea.text = tabData[tabBar.selectedIndex].textData;
textArea.selectRange(tabData[tabBar.selectedIndex].selectedAnchor, tabData[tabBar.selectedIndex].selectedActive);
if (closeAfterConfirm && tabsToClose == 0) {
FlexGlobals.topLevelApplication.close();
}
}

private function doNew():void {
statusMessage = "[ " + new Date().toLocaleTimeString() + " ] New tab created";
updateStatus();
untitledNum++;
tabData.addItem( { title:"Untitled("+untitledNum+")", textData:"", saved:false } );
tabBar.selectedIndex = tabData.length - 1;
tabChange();
}

private function tabChange():void {
tabData[previousIndex].textData = textArea.text;
tabData[previousIndex].selectedActive = textArea.selectionActivePosition;
tabData[previousIndex].selectedAnchor = textArea.selectionAnchorPosition;
previousIndex = tabBar.selectedIndex;
textArea.text = tabData[tabBar.selectedIndex].textData;
textArea.selectRange(tabData[tabBar.selectedIndex].selectedAnchor, tabData[tabBar.selectedIndex].selectedActive);
updateStatus();
}

private function tabContextClose(evt:ContextMenuEvent):void{
closeTab(rightclickTabIndex);
}

private function tabContextCloseOther(evt:ContextMenuEvent):void {
var len:int = tabData.length;
for (var i:int = 0; i < len; i++) {
if (i != rightclickTabIndex) {
closeTab(i);
}
}
}

private function tabRightClick(evt:MouseEvent):void {
var tabWidth:Number = tabBar.width / tabData.length;
var rcIndex:int = Math.floor(tabBar.mouseX / tabWidth);
rightclickTabIndex = rcIndex;
}

private function onKeyDown(evt:KeyboardEvent):void{
if (evt.ctrlKey) {
// Ctrl+TAB - next tab
if (evt.keyCode == 9 && !evt.shiftKey) {
if (tabData.length - tabBar.selectedIndex > 1) {
tabBar.selectedIndex++;
tabChange();
}
}
// Ctrl+Shift+TAB - previous tab
if (evt.keyCode == 9 && evt.shiftKey) {
if (tabBar.selectedIndex > 0) {
tabBar.selectedIndex--;
tabChange();
}
}
}
// Ctrl+number (1-8) - go to numbered tab
if (evt.keyCode >= 49 && evt.keyCode <= 56) {
var num:int = evt.keyCode - 48;
if (tabData.length > num - 1) {
tabBar.selectedIndex = num - 1;
tabChange();
}
}
// Ctrl+9 - go to last tab
if (evt.keyCode == 57) {
tabBar.selectedIndex = tabData.length - 1;
tabChange();
}
}
]]>
</fx:Script>

<fx:Declarations>
<fx:XML id="windowMenu">
<root>
<menuitem label="File">
<menuitem label="New" key="n" controlKey="true" />
<menuitem label="Open" key="o" controlKey="true" />
</menuitem>
<menuitem label="Edit">
<menuitem label="Cut" key="x" controlKey="true" />
<menuitem label="Copy" key="c" controlKey="true" />
<menuitem label="Paste" key="v" controlKey="true" />
<menuitem type="separator"/>
<menuitem label="Select all" key="a" controlKey="true" />
</menuitem>
<menuitem label="Settings">
<menuitem label="Word wrap" type="check" toggled="{pref_wrap}" />
<menuitem label="Font..."/>
</menuitem>
<menuitem label="View">
<menuitem label="Tool bar" type="check" toggled="{pref_toolbar}" />
<menuitem label="Status bar" type="check" toggled="{pref_status}" />
</menuitem>
</root>
</fx:XML>
<mx:ArrayCollection id="tabData">
<fx:Object title="Untitled" textData="" saved="false" seletedActive="0" selectedAnchor="0" />
</mx:ArrayCollection>
</fx:Declarations>

<s:Group width="100%" height="100%">
<s:TextArea id="textArea" width="100%" height="{textHeight}" y="{textY}" borderVisible="false" lineBreak="{(pref_wrap)?('toFit'):('explicit')}"  click="cursorFix(); updateStatus();" change="updateStatus();" keyDown="updateStatus();"/>
<custom:CustomTabBar id="tabBar" dataProvider="{tabData}" width="100%" y="{tabY}" itemRenderer="CustomTab" height="22" tabClose="onTabClose(event);" change="tabChange();" />
<mx:Box id="toolBar" width="100%" backgroundColor="#dddddd" height="24" visible="{pref_toolbar}">
</mx:Box>
</s:Group>

</s:WindowedApplication>

Thanks for reading!

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