Friday, February 3, 2012

Creating a Flex AIR Screenshot app: Part 13

Today we will make it so that all of the selected screens are exported and saved correctly, with correct sizes.

We will work in the exportScreen() function this whole tutorial.

The first thing we'll do is take out all the variables declarations and declare them without values in the beginning of the function. The only variable that we will give a value is folderName (since it is the only one that won't be changed - will explain later). Also add a new variable called screensToExport:

var encoder:IImageEncoder;
var bd:BitmapData;
var byteArray:ByteArray;
var folderName:String = (pref_folder)?(folderField.text):("");
var fileName:String;
var file:File;
var fileStream:FileStream;
var screensToExport:Array = [];

The next part about hanlding formats remains untouched:

if (pref_format == "JPEG") {
encoder = new JPEGEncoder(pref_quality);
}
if (pref_format == "PNG") {
encoder = new PNGEncoder();
}

Now, this is where we start to change things dramatically. We will add 2 pieces of code that add needed sizes to the screensToExport array. We need 2 of them because the first one is responsible for handling the full-size screen, and the other one is a loop which goes through all the rest screens and adds them:

// add full-size screen to array if checked
if (pref_screensizes[0].checked) {
screensToExport = [ { w:tempHTML.contentWidth, h: tempHTML.contentHeight } ];
}

// add the rest screens to array if checked
for (var i:int = 0; i < screenSettings.length; i++) {
if (pref_screensizes[i + 1].checked) {
screensToExport.push( { w: pref_screensizes[i + 1].w, h:pref_screensizes[i + 1].h } );
}
}

The array now has the screens that we need to export. Or, it may not have any elements in it at all (if no checkboxes were checked). If there are no items, add a check that stops the code and directs the user to the first screen:

// if nothing is checked, go to first page and stop code
if (screensToExport.length == 0) {
removeElement(tempHTML);
stack.selectedChild = loadpage;
return;
}

Now, this is the part where it gets tricky. You would imagine that to export images of different sizes you would have to resize the element, take its screenshot and save it, then move on to the next ones. This is true, however, to resize the element, it actually takes at least 1 frame to happen. This is why we are going to use a Timer. We set our timer with the delay of 1 second to repeat itself as many times as many items there are in the array, and set tempHTML size to the first size before starting the tiemr.

// create a timer that repeats itself as many times as many items there are in the array
var timer:Timer = new Timer(1000, screensToExport.length);
timer.addEventListener(TimerEvent.TIMER, onTimer);
// set sizes to the first size of the array
tempHTML.height = screensToExport[0].h;
tempHTML.width = screensToExport[0].w;
timer.start();

The onTimer() function that the timer is calling is an INTERNAL function, which means it is located inside exportScreen(). The other internal function is doExport(). Let's include doExport() first. You will find this code familiar:

function doExport():void {
bd = new BitmapData(tempHTML.width, tempHTML.height, false);
bd.draw(tempHTML);
byteArray = encoder.encode(bd);
fileName = pref_destination + File.separator + folderName + File.separator + tempHTML.width + "x" + tempHTML.height + "." + pref_format;
file = new File(fileName);
fileStream = new FileStream();
fileStream.open(file, FileMode.WRITE);
fileStream.writeBytes(byteArray);
fileStream.close();
}

This is the piece of code from the previous tutorial. It takes whatever the element has, takes a screenshot of it and exports it.

On each timer tick, we call this function, and thanks to the 1-second delay, we can be certain that the image is sized correctly. After we call doExport(), we need to check if this was the last element in the array, or if there are more. If there are more (we check it using timer.currentCount value), then set the size of tempHTML to the next size in the array, and wait for the next tick, and so on. If this was the last element in the array, stop the timer, remove tempHTML and go to the first page:

function onTimer(evt:TimerEvent):void {
// do export for the current size
doExport();
// change the size if this was not the last size in the array
if (timer.currentCount != screensToExport.length) {
tempHTML.height = screensToExport[timer.currentCount].h;
tempHTML.width = screensToExport[timer.currentCount].w;
}else {
// if it was the last size in the array, return to first page
timer.stop();
removeElement(tempHTML);
stack.selectedChild = loadpage;
}
}

Full function:

private function exportScreen():void {
var encoder:IImageEncoder;
var bd:BitmapData;
var byteArray:ByteArray;
var folderName:String = (pref_folder)?(folderField.text):("");
var fileName:String;
var file:File;
var fileStream:FileStream;
var screensToExport:Array = [];

if (pref_format == "JPEG") {
encoder = new JPEGEncoder(pref_quality);
}
if (pref_format == "PNG") {
encoder = new PNGEncoder();
}

// add full-size screen to array if checked
if (pref_screensizes[0].checked) {
screensToExport = [ { w:tempHTML.contentWidth, h: tempHTML.contentHeight } ];
}

// add the rest screens to array if checked
for (var i:int = 0; i < screenSettings.length; i++) {
if (pref_screensizes[i + 1].checked) {
screensToExport.push( { w: pref_screensizes[i + 1].w, h:pref_screensizes[i + 1].h } );
}
}

// if nothing is checked, go to first page and stop code
if (screensToExport.length == 0) {
removeElement(tempHTML);
stack.selectedChild = loadpage;
return;
}

// create a timer that repeats itself as many times as many items there are in the array
var timer:Timer = new Timer(1000, screensToExport.length);
timer.addEventListener(TimerEvent.TIMER, onTimer);
// set sizes to the first size of the array
tempHTML.height = screensToExport[0].h;
tempHTML.width = screensToExport[0].w;
timer.start();

function onTimer(evt:TimerEvent):void {
// do export for the current size
doExport();
// change the size if this was not the last size in the array
if (timer.currentCount != screensToExport.length) {
tempHTML.height = screensToExport[timer.currentCount].h;
tempHTML.width = screensToExport[timer.currentCount].w;
}else {
// if it was the last size in the array, return to first page
timer.stop();
removeElement(tempHTML);
stack.selectedChild = loadpage;
}
}

function doExport():void {
bd = new BitmapData(tempHTML.width, tempHTML.height, false);
bd.draw(tempHTML);
byteArray = encoder.encode(bd);
fileName = pref_destination + File.separator + folderName + File.separator + tempHTML.width + "x" + tempHTML.height + "." + pref_format;
file = new File(fileName);
fileStream = new FileStream();
fileStream.open(file, FileMode.WRITE);
fileStream.writeBytes(byteArray);
fileStream.close();
}
}

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:custom="*"
                       xmlns:mx="library://ns.adobe.com/flex/mx" showStatusBar="false"
   width="550" height="600" creationComplete="init();">
   
   
<fx:Declarations>
<mx:ArrayCollection id="headerTitles">
<fx:Object step="Step one:" description="load a web page." />
<fx:Object step="Loading..." description="please wait." />
<fx:Object step="Step two:" description="set your export preferences." />
<fx:Object step="Step two:" description="select the area you wish to crop." />
<fx:Object step="Step three:" description="set your export preferences for the cropped image." />
</mx:ArrayCollection>
</fx:Declarations>

<fx:Style>
@namespace s "library://ns.adobe.com/flex/spark";
@namespace mx "library://ns.adobe.com/flex/mx";

.descriptionText{
fontSize: 24;
color: #fff;
}

.descriptionText2{
fontSize: 16;
color: #fff;
}

.settingText{
fontSize: 16;
color: #fff;
}

#headStep{
fontSize: 30;
fontWeight: bold;
color: #ffffbb;
}

#headDesc{
fontSize: 30;
color: #ffffff;
}
</fx:Style>

<fx:Script>
<![CDATA[
import flash.display.Bitmap;
import flash.display.BitmapData;
import flash.events.Event;
import flash.events.MouseEvent;
import flash.events.TimerEvent;
import flash.filesystem.File;
import flash.filesystem.FileStream;
import flash.geom.Rectangle;
import flash.net.URLRequest;
import flash.utils.ByteArray;
import flash.utils.Timer;
import mx.controls.HTML;
import mx.core.FlexHTMLLoader;
import mx.events.FlexNativeWindowBoundsEvent;
import mx.controls.Alert;
import mx.events.ResizeEvent;
import mx.graphics.codec.IImageEncoder;
import mx.graphics.codec.JPEGEncoder;
import mx.graphics.codec.PNGEncoder;
import mx.graphics.ImageSnapshot;
import spark.primitives.BitmapImage;
import flash.filesystem.FileMode;
import mx.managers.PopUpManager;

[Bindable]
private var urlString:String;
[Bindable]
private var canSelect:Boolean = true;
private var tempHTML:HTML = new HTML();

private var preferences:SharedObject = SharedObject.getLocal("kirshotPreferences");
[Bindable]
private var pref_screensizes:Array;
[Bindable]
private var pref_format:String;
[Bindable]
private var pref_quality:int;
[Bindable]
private var pref_folder:Boolean;
[Bindable]
private var pref_destination:String;

private var screenSettings:Array;

private function init():void {
//preferences.data.firsttime = null;

// Set preferences if loaded for the first time
if (preferences.data.firsttime == null) {
preferences.data.firsttime = true;
preferences.data.screensizes = [ 
{ checked:true },
{ checked:true, w:1280, h:1024 },
{ checked:true, w:1280, h:800 },
{ checked:true, w:1024, h:768 },
{ checked:false, w:"", h:"" },
{ checked:false, w:"", h:"" },
{ checked:false, w:"", h:"" } ];
preferences.data.format = "JPEG";
preferences.data.quality = 100;
preferences.data.folder = true;
preferences.data.destination = File.documentsDirectory.nativePath;
preferences.flush();
}

// Set preferences loaded from local storage
pref_screensizes = preferences.data.screensizes;
pref_format = preferences.data.format;
pref_quality = preferences.data.quality;
pref_folder = preferences.data.folder;
pref_destination = preferences.data.destination;

addEventListener(FlexNativeWindowBoundsEvent.WINDOW_RESIZE, onResize);
}

private function doBrowse():void{
var file:File = new File();
file.addEventListener(Event.SELECT, browseSelect);
file.browseForOpen("Load a webpage");

function browseSelect(evt:Event):void {
urlInput.text = file.nativePath;
}
}

private function goCrop():void {
stack.selectedChild = crop;
urlString = urlInput.text;
}

private function goScreenshot():void {
stack.selectedChild = screenshotloading;
urlString = urlInput.text;

addElement(tempHTML);
tempHTML.visible = false;
tempHTML.addEventListener(Event.COMPLETE, onTempLoad);
tempHTML.htmlLoader.load(new URLRequest(urlString));
}

private function onTempLoad(evt:Event):void {
stack.selectedChild = screenshotsettings;
}

private function cancelLoading():void {
tempHTML.removeEventListener(Event.COMPLETE, onTempLoad);
tempHTML.cancelLoad();
screenshotBack();
}

private function screenshotBack():void {
saveScreenshotSettings()
stack.selectedChild = loadpage;
removeElement(tempHTML);
}

private function changeState():void {
if (stack.selectedChild == loadpage) {
contentBox.setStyle("horizontalAlign", "center");
urlInput.text = urlString;
}
if (stack.selectedChild == crop) {
maximize();
canSelect = true;
contentBox.setStyle("horizontalAlign", "left");
cropHTML.htmlLoader.load(new URLRequest(urlString));
cropHTML.width = contentBox.width;
cropHTML.height = contentBox.height - 24;
cropStatus.text = "Loading";
cropStatus.setStyle("color", "#ffff00");
cropHTML.addEventListener(Event.COMPLETE, onCropLoad);
}
if (stack.selectedChild == screenshotsettings) {
screenSettings = [set2, set3, set4, set5, set6, set7];
contSize.text = "Full size (" + tempHTML.contentWidth + "x" + tempHTML.contentHeight + ")";
loadScreenshotSettings();
}
}

private function loadScreenshotSettings():void {
set1checkbox.selected = pref_screensizes[0].checked;

for (var i:int = 0; i < screenSettings.length; i++) {
screenSettings[i].checked = pref_screensizes[i + 1].checked;
screenSettings[i].w = pref_screensizes[i + 1].w;
screenSettings[i].h = pref_screensizes[i + 1].h;
}

if (pref_format == "JPEG") {
screenRadioJPEG.selected = true;
} else {
screenRadioPNG.selected = true;
}
}

private function saveScreenshotSettings():void {
pref_screensizes[0].checked = set1checkbox.selected;

for (var i:int = 0; i < screenSettings.length; i++) {
pref_screensizes[i + 1].checked = screenSettings[i].checked;
pref_screensizes[i + 1].w = screenSettings[i].w;
pref_screensizes[i + 1].h = screenSettings[i].h;
}

if (screenRadioJPEG.selected == true) {
pref_format == "JPEG";
} else {
pref_format == "PNG";
}

preferences.data.screensizes = pref_screensizes;
preferences.data.format = pref_format;
preferences.data.quality = pref_quality;
preferences.data.folder = pref_folder;
preferences.data.destination = pref_destination;
preferences.flush();
}

private function formatChange(newformat:String):void {
pref_format = newformat;
}

private function startExportScreenshot():void {
var canExport:Boolean = true;

for (var i:int = 0; i < screenSettings.length; i++) {
if (screenSettings[i].checked && ((screenSettings[i].w == "" || screenSettings[i].w == 0) || (screenSettings[i].h == "" || screenSettings[i].h == 0))) {
canExport = false;
}
}

if (canExport) {
if ((pref_folder && folderField.text != "") || !pref_folder) {
saveScreenshotSettings();
exportScreen();
}else {
Alert.show("Folder name should not be blank!", "Oops...");
}
}else {
Alert.show("One or more selected screen sizes are not entered or are invalid!", "Oops...");
}
}

private function screenshotDestination():void {
var newDestination:File = new File(pref_destination);
newDestination.browseForDirectory("Select directory");
newDestination.addEventListener(Event.SELECT, destinationSelect);

function destinationSelect(evt:Event):void {
pref_destination = newDestination.nativePath;
}
}

private function exportScreen():void {
var encoder:IImageEncoder;
var bd:BitmapData;
var byteArray:ByteArray;
var folderName:String = (pref_folder)?(folderField.text):("");
var fileName:String;
var file:File;
var fileStream:FileStream;
var screensToExport:Array = [];

if (pref_format == "JPEG") {
encoder = new JPEGEncoder(pref_quality);
}
if (pref_format == "PNG") {
encoder = new PNGEncoder();
}

// add full-size screen to array if checked
if (pref_screensizes[0].checked) {
screensToExport = [ { w:tempHTML.contentWidth, h: tempHTML.contentHeight } ];
}

// add the rest screens to array if checked
for (var i:int = 0; i < screenSettings.length; i++) {
if (pref_screensizes[i + 1].checked) {
screensToExport.push( { w: pref_screensizes[i + 1].w, h:pref_screensizes[i + 1].h } );
}
}

// if nothing is checked, go to first page and stop code
if (screensToExport.length == 0) {
removeElement(tempHTML);
stack.selectedChild = loadpage;
return;
}

// create a timer that repeats itself as many times as many items there are in the array
var timer:Timer = new Timer(1000, screensToExport.length);
timer.addEventListener(TimerEvent.TIMER, onTimer);
// set sizes to the first size of the array
tempHTML.height = screensToExport[0].h;
tempHTML.width = screensToExport[0].w;
timer.start();

function onTimer(evt:TimerEvent):void {
// do export for the current size
doExport();
// change the size if this was not the last size in the array
if (timer.currentCount != screensToExport.length) {
tempHTML.height = screensToExport[timer.currentCount].h;
tempHTML.width = screensToExport[timer.currentCount].w;
}else {
// if it was the last size in the array, return to first page
timer.stop();
removeElement(tempHTML);
stack.selectedChild = loadpage;
}
}

function doExport():void {
bd = new BitmapData(tempHTML.width, tempHTML.height, false);
bd.draw(tempHTML);
byteArray = encoder.encode(bd);
fileName = pref_destination + File.separator + folderName + File.separator + tempHTML.width + "x" + tempHTML.height + "." + pref_format;
file = new File(fileName);
fileStream = new FileStream();
fileStream.open(file, FileMode.WRITE);
fileStream.writeBytes(byteArray);
fileStream.close();
}
}

private function onCropLoad(evt:Event):void {
cropStatus.text = "Loaded";
cropStatus.setStyle("color", "#ffffff");
}

private function onResize(evt:Event):void {
if (stack.selectedChild == crop) {
cropHTML.width = contentBox.width;
cropHTML.height = contentBox.height - 24;
}
}
]]>
</fx:Script>
   
<s:VGroup width="100%" height="100%" gap="0">
<mx:HBox backgroundColor="#333333" height="46" width="100%" paddingTop="10" paddingLeft="10">
<s:Label id="headStep" text="{headerTitles.getItemAt(stack.selectedIndex).step}" />
<s:Label id="headDesc" text="{headerTitles.getItemAt(stack.selectedIndex).description}" />
</mx:HBox>
<mx:Box backgroundColor="#666666" width="100%" height="100%" id="contentBox" horizontalAlign="center">
<mx:ViewStack id="stack" change="changeState();">
<s:NavigatorContent id="loadpage">
<s:VGroup width="100%" horizontalAlign="center" paddingTop="20">
<s:Label styleName="descriptionText">Enter the link to the page:</s:Label>
<s:HGroup>
<s:TextInput width="250" id="urlInput" text="http://" /><s:Button label="Browse local..." click="doBrowse();" />
</s:HGroup>
<s:HGroup>
<custom:ImageButton img="@Embed('../lib/b_screenshot.png')" over="@Embed('../lib/b_screenshot_over.png')" toolTip="Take screenshots" click="goScreenshot();" buttonMode="true" enabled="{urlInput.text!=''}" />
<custom:ImageButton img="@Embed('../lib/b_cut.png')" over="@Embed('../lib/b_cut_over.png')" toolTip="Crop area" click="goCrop();" buttonMode="true" enabled="{urlInput.text!=''}" />
</s:HGroup>
</s:VGroup>
</s:NavigatorContent>

<s:NavigatorContent id="screenshotloading">
<s:VGroup width="100%" horizontalAlign="center" paddingTop="20">
<s:Label styleName="descriptionText">The page is being loaded...</s:Label>
<s:Button label="Cancel" click="cancelLoading();" />
</s:VGroup>
</s:NavigatorContent>

<s:NavigatorContent id="screenshotsettings">
<s:VGroup width="100%" horizontalAlign="center" paddingTop="20">
<s:Label styleName="descriptionText2">Select screenshot screen sizes:</s:Label>
<s:SkinnableContainer backgroundColor="#999999" width="310" height="18" >
<s:CheckBox toolTip="Use this screen size" x="4" id="set1checkbox" />
<s:Label id="contSize" styleName="settingText" x="22" y="3" />
</s:SkinnableContainer>
<custom:ScreenSetting id="set2" />
<custom:ScreenSetting id="set3" />
<custom:ScreenSetting id="set4" />
<custom:ScreenSetting id="set5" />
<custom:ScreenSetting id="set6" />
<custom:ScreenSetting id="set7" />

<s:Label/>

<s:Label styleName="descriptionText2">Export as:</s:Label>
<s:HGroup>
<s:RadioButton id="screenRadioJPEG" label="JPEG" groupName="screenshotFormat" change="formatChange('JPEG');" styleName="descriptionText2" /> 
<s:RadioButton id="screenRadioPNG" label="PNG" groupName="screenshotFormat" change="formatChange('PNG');" styleName="descriptionText2" /> 
</s:HGroup>
<s:Label styleName="descriptionText2">Quality:</s:Label>
<s:HSlider id="screenQualitySlider" width="310" minimum="1" maximum="100" liveDragging="true" enabled="{pref_format=='JPEG'}" value="@{pref_quality}" />

<s:Label/>

<s:Label styleName="descriptionText2">Export destination:</s:Label>
<s:HGroup width="310">
<s:TextInput editable="false" width="100%" toolTip="Destination" text="{pref_destination}" />
<s:Button label="Browse" click="screenshotDestination();" />
</s:HGroup>
<s:CheckBox id="folderCheckbox" label="Create new folder with exported images" styleName="descriptionText2" selected="@{pref_folder}" />
<s:TextInput id="folderField" width="100%" toolTip="Folder name" maxChars="200" enabled="{folderCheckbox.selected}" restrict="a-zA-Z0-9._-=+" />
<s:HGroup>
<s:Button label="Back" click="screenshotBack();" />
<s:Button label="Export" click="startExportScreenshot();" />
</s:HGroup>
</s:VGroup>
</s:NavigatorContent>

<s:NavigatorContent id="crop">
<s:VGroup width="100%" height="100%" gap="0">
<mx:HBox backgroundColor="#999999" width="100%" height="24" verticalScrollPolicy="off" verticalAlign="middle" paddingLeft="2">
<s:Button label="Back" click="{cropHTML.htmlLoader.loadString(''); stack.selectedChild = loadpage;}" />
<s:Button label="Export selection" enabled="false" />
<s:Label id="cropStatus" />
<s:Label text="{urlString}" />
</mx:HBox>
<mx:HTML id="cropHTML" horizontalScrollPolicy="on" verticalScrollPolicy="on" />
</s:VGroup>
</s:NavigatorContent>

<s:NavigatorContent id="cropsettings">

</s:NavigatorContent>
</mx:ViewStack>
</mx:Box>
</s:VGroup>

</s:WindowedApplication>

Note that while the export is in process, the user is still able to interract with the interface of the settings page. We'll fix that in the next tutorial.

Thanks for reading!

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