Tuesday, January 31, 2012

Creating a Flex AIR Screenshot app: Part 10

In this tutorial we're going to add more options to the screenshot settings page.

We need to add more export settings for the user to configure, specifically - we need to add an ability to choose exported image's format - JPEG or PNG, as well as its quality, if JPEG was chosen.

Go to the screenshotsettings NavigatorContent object and add a HGroup containing 2 radio button objects. Set their ids to screenRadioJPEG and screenRadioPNG, labels to JPEG and PNG, groupName to screenshotFormat. Call formatChange() on change event, pass "JPEG" or "PNG" as the parameter for that function.

<s:HGroup>
<s:RadioButton id="screenRadioJPEG" label="JPEG" groupName="screenshotFormat" change="formatChange('JPEG');" /> 
<s:RadioButton id="screenRadioPNG" label="PNG" groupName="screenshotFormat" change="formatChange('PNG');" /> 
</s:HGroup>

Then add a HSlider object with id of screenQualitySlider. Set its minimum value to 1, maximum to 100 and liveDragging to true. Binding this object's 'enabled' property to {pref_format=='JPEG'} will make sure that it is only enabled if JPEG format is chosen. Two-way-bind its 'value' property to a variable called pref_quality.

<s:Label>Quality:</s:Label>
<s:HSlider id="screenQualitySlider" width="310" minimum="1" maximum="100" liveDragging="true" enabled="{pref_format=='JPEG'}" value="@{pref_quality}" />

The whole NavigatorContent object now looks like this:

<s:NavigatorContent id="screenshotsettings">
<s:VGroup width="100%" horizontalAlign="center" paddingTop="20">
<s:Label styleName="descriptionText">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:HGroup>
<s:RadioButton id="screenRadioJPEG" label="JPEG" groupName="screenshotFormat" change="formatChange('JPEG');" /> 
<s:RadioButton id="screenRadioPNG" label="PNG" groupName="screenshotFormat" change="formatChange('PNG');" /> 
</s:HGroup>
<s:Label>Quality:</s:Label>
<s:HSlider id="screenQualitySlider" width="310" minimum="1" maximum="100" liveDragging="true" enabled="{pref_format=='JPEG'}" value="@{pref_quality}" />
<s:HGroup>
<s:Button label="Back" click="screenshotBack();" />
<s:Button label="Export" click="startExportScreenshot();" />
</s:HGroup>
</s:VGroup>
</s:NavigatorContent>

Now let's go and declare 2 variables - pref_format and pref_quality:

[Bindable]
private var pref_format:String;
[Bindable]
private var pref_quality:int;

In the init() function, add lines to set default values for format and quality, as well as apply all the pref_ variables to preferences shared object's values:

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.flush();
}

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

addEventListener(FlexNativeWindowBoundsEvent.WINDOW_RESIZE, onResize);
}

Make sure to uncomment preferences.data.firsttime = null; for the first time running this code to make sure the default values are updated! Do that after the code of this tutorial is complete.

Let's create this formatChange() function, which has a string parameter. Set pref_format to this value:

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

Update loadScreenshotSettings() by adding a check to select JPEG or PNG radio button when the page is opened:

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;
}
}

Now update saveScreenshotSettings() by adding the same check, as well as update all the data properties of preferences object to pref_ variables' values:

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.flush();
}

And that's all! Now the user can choose a format and quality, and he can be sure that the values he sets will be saved and loaded the next time he launches the application.

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="500" 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." />
<fx:Object step="Final step:" description="please wait while your images are being expored." />
</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;
}

.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.filesystem.File;
import flash.geom.Rectangle;
import flash.net.URLRequest;
import mx.controls.HTML;
import mx.core.FlexHTMLLoader;
import mx.events.FlexNativeWindowBoundsEvent;
import mx.controls.Alert;
import mx.graphics.codec.JPEGEncoder;
import mx.graphics.codec.PNGEncoder;
import mx.graphics.ImageSnapshot;
import spark.primitives.BitmapImage;

[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;
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.flush();
}

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

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.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) {
Alert.show("Successful export");
}else {
Alert.show("One or more selected screen sizes are not entered or are invalid!", "Oops...");
}
}

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

<s:NavigatorContent id="export">

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

</s:WindowedApplication>

Thanks for reading!

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