Thursday, October 27, 2011

Creating a Flex AIR text editor: Part 17

In this tutorial we are going to add hotkeys to let the user navigate through tabs using keyboard.

First of all, though, we will add a few lines to our existing code to update the status bar with status messages. Let's do this when we create a new tab (the doNew() function):

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

And also when we remove one:

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);
}

There we go. Now we actually can say that we have a use for the status messages area in our status bar :)

Now let's add hotkeys to let the user navigate through the tabs using keyboard. There are a few combinations we are going to implement:

Ctrl+Tab will open the next tab.
Ctrl+Shift+Tab will go to the previous tab.
Ctrl+(1-8) will go to the numbered tab (from 1 to 8).
Ctrl+9 will go to the last tab.

Let's implement this now. Add a listener for the keyboard events in the init() function:

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

All the key combinations right now require the Ctrl key to be pressed. Let's make a conditional for that:

private function onKeyDown(evt:KeyboardEvent):void{
if (evt.ctrlKey) {

}
}

Now we can write the conditionals for each of the combination. Here's the full function in the end:

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();
}
}

It is important to call tabChange() every time we change the tab so that the data gets updated.

Here's the 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;

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;

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 {
var allWindows:Array = NativeApplication.nativeApplication.openedWindows;
for (var i:int = 0; i < allWindows.length; i++)
{
allWindows[i].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 {
if (evt.detail == Alert.YES) {
Alert.show("Perform save function here and then delete");
}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);
}

private function doNew():void {
statusMessage = "[ " + new Date().toLocaleTimeString() + " ] New tab created";
updateStatus();
tabData.addItem( { title:"Untitled", 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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