Saturday, November 5, 2011

Creating a Flex AIR text editor: Part 26

In this tutorial we are going to optimize our existing line numeration code, as well as synchronize line enumeration bar and text area scrolling.

First go to the lineCount text area object, set its horizontal and vertical policies to off:

<s:TextArea id="lineCount" width="{lineCountWidth}" text="{lineNumbers}" visible="{pref_linecount}" height="{textHeight}" y="{textY}" editable="false" selectable="false" mouseEnabled="false" textAlign="right" verticalScrollPolicy="off" horizontalScrollPolicy="off" />

Find your everyFrame function. Here we can call an updateLineScroll() function. It will be a small function and will not eat up CPU or take lots of memory:

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

The updateLineScroll function synchronizes the scrolling of the lineCount text area and the textArea text area:

private function updateLineScroll():void{
lineCount.scroller.verticalScrollBar.value = textArea.scroller.verticalScrollBar.value;
}

Before, we had our code that enumerates the lines refresh completely after each change. This is very intensive ont he hardware, especially if there are a lot of lines. I managed to make the algorithm lighter and not as expensive. Instead of updating from blank, it just adds or substracts the needed numbers from the current value. Take a look:

private function countLines():void {
if (pref_linecount && !pref_wrap) {
var totalLines:int = textArea.text.split("\n").length;
if (totalLines != lineDisplayedNum) {
updateTextSize();
updateLineCount(totalLines, totalLines-lineDisplayedNum, lineDisplayedNum);
lineDisplayedNum = totalLines;
}
}
}

private function updateLineCount(total:int, difference:int, current:int):void {
if (difference > 0) {
for (var i:int = current + 1; i < (total+1); i++) {
lineNumbers += "\n" + (i);
}
}
if (difference < 0) {
var charsInTheEnd:int = 0;
for (var u:int = 0; u < -difference; u++) {
charsInTheEnd += ((current - u).toString().length + 1);
}
lineNumbers = lineCount.text.substring(0, lineCount.text.length - charsInTheEnd);
}
}

If the difference between real total lines and displayed lines is positive, then we need to add a few lines to the bar. If the difference is negative, we need to take some of the lines away - I do that by calculating how many symbols I need to take away and then get rid of them using the substring function.

That's all for today.

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}"
   minWidth="400" minHeight="200" height="700" width="900">
   
<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]
private var pref_sidepane:Boolean = true;
[Bindable]
private var pref_linecount: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 textWidth:Number;
[Bindable]
private var textY:Number;
[Bindable]
private var textX:Number;
[Bindable]
private var tabY:Number;
[Bindable]
private var sidePaneY:Number;
[Bindable]
private var sidePaneX:Number;
[Bindable]
private var sidePaneHeight:Number;
[Bindable]
private var sidePaneWidth:Number = 180;
[Bindable]
private var sideContentWidth:Number = 170;
[Bindable]
private var tabWidth:Number;
[Bindable]
private var lineCountWidth:Number = 40;
[Bindable]
private var lineNumbers:String = "1";
[Bindable]
private var lineDisplayedNum:int = 1;

[Bindable]
private var tabSelectedIndex:int = 0;

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;

preferences.data.firsttime = null;

// Set preferences if loaded for the first time
if (preferences.data.firsttime == null) {
preferences.data.firsttime = true;
preferences.data.wrap = false;
preferences.data.status = true;
preferences.data.toolbar = true;
preferences.data.sidepane = true;
preferences.data.linecount = 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_sidepane = preferences.data.sidepane;
pref_fontsettings = preferences.data.fontsettings;
pref_linecount = preferences.data.linecount;

// 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 == "Side pane")?(pref_sidepane = !pref_sidepane):(void);
(evt.item.@label == "Line count")?(pref_linecount = !pref_linecount):(void);
(evt.item.@label == "Font...")?(doFont()):(void);
savePreferences();
updateStatus();
if (pref_wrap) {
pref_linecount = false;
}
updateTextSize();
countLines();
}

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.data.sidepane = pref_sidepane;
preferences.data.linecount = pref_linecount;
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();
}
}
updateLineScroll();
}

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

private function updateTextSize():void {
tabY = (toolBar.visible)?(toolBar.height):(0);
textY = tabBar.height + tabY;
textX = (pref_linecount)?(lineCountWidth):(0);
var statusHeight:Number = (pref_status)?(statusBar.height):(0);
textHeight = height - textY - statusHeight;
textWidth = (pref_sidepane)?(width - sidePaneWidth - textX):(width - textX);
tabWidth = textWidth + textX;
focusManager.setFocus(textArea);
sidePaneHeight = textHeight + tabBar.height;
sidePaneY = textY-tabBar.height;
sidePaneX = width - sidePaneWidth;
}

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);

lineCount.setStyle("fontFamily", pref_fontsettings.fontfamily);
lineCount.setStyle("fontSize", pref_fontsettings.fontsize);
lineCount.setStyle("fontStyle", pref_fontsettings.fontstyle);
lineCount.setStyle("fontWeight", pref_fontsettings.fontweight);
lineCount.setStyle("color", pref_fontsettings.fontcolor);
lineCount.setStyle("contentBackgroundColor", pref_fontsettings.bgcolor);
}

private function onTabClose(evt:Event):void {
var tabWidth:Number = tabBar.width / tabData.length;
var cIndex:int = Math.floor(tabBar.mouseX / tabWidth);
tabSelectedIndex = cIndex;
tabChange();
closeTab(tabSelectedIndex);
}

private function onListClose(evt:Event):void {
tabSelectedIndex = sideList.selectedIndex;
tabChange();
closeTab(tabSelectedIndex);
}

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);
tabSelectedIndex = tabBar.selectedIndex;
previousIndex = tabSelectedIndex;
textArea.text = tabData[tabSelectedIndex].textData;
textArea.selectRange(tabData[tabSelectedIndex].selectedAnchor, tabData[tabSelectedIndex].selectedActive);
if (closeAfterConfirm && tabsToClose == 0) {
FlexGlobals.topLevelApplication.close();
}
countLines();
}

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

private function tabChange(from:String = "none"):void {
if (from == "tabbar") {
tabSelectedIndex = tabBar.selectedIndex;
}
if (from == "sidelist") {
tabSelectedIndex = sideList.selectedIndex;
}
tabData[previousIndex].textData = textArea.text;
tabData[previousIndex].selectedActive = textArea.selectionActivePosition;
tabData[previousIndex].selectedAnchor = textArea.selectionAnchorPosition;
previousIndex = tabSelectedIndex;
textArea.text = tabData[tabSelectedIndex].textData;
textArea.selectRange(tabData[tabSelectedIndex].selectedAnchor, tabData[tabSelectedIndex].selectedActive);
updateStatus();
countLines();
}

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 - tabSelectedIndex > 1) {
tabSelectedIndex++;
tabChange();
}
}
// Ctrl+Shift+TAB - previous tab
if (evt.keyCode == 9 && evt.shiftKey) {
if (tabSelectedIndex > 0) {
tabSelectedIndex--;
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) {
tabSelectedIndex = num - 1;
tabChange();
}
}
// Ctrl+9 - go to last tab
if (evt.keyCode == 57) {
tabSelectedIndex = tabData.length - 1;
tabChange();
}
}
}

private function closeSidePane():void{
pref_sidepane = !pref_sidepane
savePreferences();
updateTextSize();
}

private function countLines():void {
if (pref_linecount && !pref_wrap) {
var totalLines:int = textArea.text.split("\n").length;
if (totalLines != lineDisplayedNum) {
updateTextSize();
updateLineCount(totalLines, totalLines-lineDisplayedNum, lineDisplayedNum);
lineDisplayedNum = totalLines;
}
}
}

private function updateLineCount(total:int, difference:int, current:int):void {
if (difference > 0) {
for (var i:int = current + 1; i < (total+1); i++) {
lineNumbers += "\n" + (i);
}
}
if (difference < 0) {
var charsInTheEnd:int = 0;
for (var u:int = 0; u < -difference; u++) {
charsInTheEnd += ((current - u).toString().length + 1);
}
lineNumbers = lineCount.text.substring(0, lineCount.text.length - charsInTheEnd);
}
}

private function updateLineScroll():void{
lineCount.scroller.verticalScrollBar.value = textArea.scroller.verticalScrollBar.value;
}
]]>
</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 label="Line count" type="check" toggled="{pref_linecount}" />
<menuitem label="Side pane" type="check" toggled="{pref_sidepane}" />
</menuitem>
</root>
</fx:XML>
<mx:ArrayCollection id="tabData">
<fx:Object title="Untitled" textData="" saved="false" seletedActive="0" selectedAnchor="0" />
</mx:ArrayCollection>
<mx:ArrayCollection id="sidePaneData">
<fx:Object icon="@Embed('../lib/page.png')" tip="Tab management" />
<fx:Object icon="@Embed('../lib/folder_magnify.png')" tip="File browsing" />
<fx:Object icon="@Embed('../lib/book.png')" tip="Snippets" />
</mx:ArrayCollection>
<mx:ArrayCollection id="sidePaneTabHeadings">
<fx:String>Tab management</fx:String>
<fx:String>File browsing</fx:String>
<fx:String>Snippets</fx:String>
</mx:ArrayCollection>
</fx:Declarations>

<s:Group width="100%" height="100%">
<s:TextArea id="textArea" width="{textWidth}" height="{textHeight}" y="{textY}" x="{textX}" borderVisible="false" lineBreak="{(pref_wrap)?('toFit'):('explicit')}"  click="cursorFix(); updateStatus();" change="updateStatus(); countLines();" keyDown="updateStatus();"/>
<custom:CustomTabBar id="tabBar" dataProvider="{tabData}" width="{tabWidth}" y="{tabY}" itemRenderer="CustomTab" height="22" tabClose="onTabClose(event);" change="tabChange('tabbar');" selectedIndex="{tabSelectedIndex}"/>
<s:TextArea id="lineCount" width="{lineCountWidth}" text="{lineNumbers}" visible="{pref_linecount}" height="{textHeight}" y="{textY}" editable="false" selectable="false" mouseEnabled="false" textAlign="right" verticalScrollPolicy="off" horizontalScrollPolicy="off" />
<mx:Box id="toolBar" width="100%" backgroundColor="#dddddd" height="24" visible="{pref_toolbar}">
</mx:Box>
<mx:Box id="sidePane" width="{sidePaneWidth}" y="{sidePaneY}" x="{sidePaneX}" height="{sidePaneHeight}" backgroundColor="#dddddd" visible="{pref_sidepane}" paddingTop="5" paddingLeft="5" horizontalScrollPolicy="off">
<s:Group>
<s:Label text="{sidePaneTabHeadings.getItemAt(sidePaneButtons.selectedIndex)}" width="{sidePaneWidth}" />
<mx:Image source="@Embed('../lib/bullet_go.png')" top="-4" right="15" click="closeSidePane();" useHandCursor="true" buttonMode="true"/>
</s:Group>
<mx:ToggleButtonBar id="sidePaneButtons" dataProvider="{sidePaneData}" iconField="icon" width="{sidePaneWidth-10}" toolTipField="tip" />
<mx:ViewStack id="sidePaneStack" height="100%" selectedIndex="{sidePaneButtons.selectedIndex}">
<s:NavigatorContent id="tabs">
<custom:CustomList id="sideList" dataProvider="{tabData}" width="{sideContentWidth}" height="100%" itemRenderer="CustomListItem" selectedIndex="{tabSelectedIndex}" change="tabChange('sidelist');" tabClose="onListClose(event);"/>
</s:NavigatorContent>
<s:NavigatorContent id="files">
<mx:FileSystemTree height="100%" width="100%" />
</s:NavigatorContent>
<s:NavigatorContent id="snippets">
<s:VGroup height="100%" width="100%">
<mx:Tree height="100%" width="100%" />
<s:Button width="100%" label="New snippet" />
<s:Button width="100%" label="Manage snippets" />
</s:VGroup>
</s:NavigatorContent>
</mx:ViewStack>
</mx:Box>
</s:Group>

</s:WindowedApplication>

Thanks for reading.

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