I would like to display an Image using a Bitmap as source. I've been suggested something akin to this but somehow it still doesn't work.
img1 works fine... But img2 doesn't load for some reason.
private function onComplete(event:Event):void{
_bytes = event.target.data;
img1.source = _bytes; /*this last bit works*/
_bmpData = new BitmapData(img1.width,img1.height);
_bmpData.draw(img1,new Matrix());
_bmp = new Bitmap(_bmpData);
img2.source=_bmp;
}
img2.source=_bmp; doesn't work because you can't pass a Bitmap object to the source property of an Image control. From the documentation:
The value of the source property represents a relative or absolute URL; a ByteArray representing a SWF, GIF, JPEG, or PNG; an object that implements IFlexDisplayObject; a class whose type implements IFlexDisplayObject; or a String that represents a class.
A Bitmap is a DisplayObject, but it does not implement IFlexDisplayObject, so instead of using Image.source you can add the Bitmap as a child of the Image:
img2.addChild(_bmp);
Related
I want to use SVG images as icons on a TabbedPage in Xamarin.Forms for iOS.
The documentation for the TabbedPage class provides the following tip:
The TabbedRenderer for iOS has an overridable GetIcon method that can be used to load tab icons from a specified source. This override makes it possible to use SVG images as icons on a TabbedPage. In addition, selected and unselected versions of an icon can be provided.
I created the following class to perform the override:
[assembly: ExportRenderer(typeof(TabsRoot), typeof(TabbedPageCustomRenderer))]
namespace MyProject.iOS.Renderers
{
public class TabbedPageCustomRenderer : TabbedRenderer
{
protected override Task<Tuple<UIImage, UIImage>> GetIcon(Page page)
{
var image = UIImage.FromFile(#"home-black-18dp.svg");
return Task.FromResult(new Tuple<UIImage, UIImage>(image, image));
}
}
}
The accepted answer in this thread recommends creating a UIImage from an SVG file by doing something like this: var myImage = UIImage.FromFile(<<file name>>) where <<filename>> is an SVG. This other thread contradicts the previous thread, saying that UIImages cannot be made from SVG files. Sure enough, when I provide an SVG file, UIImage.FromFile() returns null and no icon is shown at all, just as the latter thread predicted. When I provide a PNG file, the override works as expected.
Another way I've tried to square this circle is to use the SvgCachedImage provided by FFImageLoading.Svg.Forms, but I haven't figured out how to 'wrap' a UIImage around an SvgCachedImage or whether that is even appropriate in this case.
Thank you for your help!
Add Xamarin.FFImageLoading.Svg nuget package to your ios project.
then create the UImage in your GetIcon method like below :
UIImage img = await ImageService.Instance
.LoadFile("timer.svg")
.WithCustomDataResolver(new SvgDataResolver((int)(TabBar?.Bounds.Height / 2 ?? 30), (int)(TabBar?.Bounds.Height / 2 ?? 30), false))
.AsUIImageAsync();
UIImage newImg = img.ImageWithRenderingMode(UIImageRenderingMode.AlwaysOriginal);
I have created an image on a Canvas which is scaled down for display using a transformation. It is also in a ScrollPane which means only a part of the image is visible.
I need to take a snapshot of the entire canvas and save this as a high-resolution image. When I use Canvas.snapshot I get a Writable image of the visible part of the image after scaling down. This results in a low-res partial image being saved.
So how do I go about creating a snapshot which includes the entire canvas (not only the viewport of the scrollpane) and with the resolution before the transformation downwards?
I am not doing anything fancy currently, just this:
public WritableImage getPackageCanvasSnapshot()
{
SnapshotParameters param = new SnapshotParameters();
param.setDepthBuffer(true);
return packageCanvas.snapshot(param, null);
}
I did the following to get a canvas snapshot on a Retina display with a pixelScaleFactor of 2.0. It worked for me.
public static WritableImage pixelScaleAwareCanvasSnapshot(Canvas canvas, double pixelScale) {
WritableImage writableImage = new WritableImage((int)Math.rint(pixelScale*canvas.getWidth()), (int)Math.rint(pixelScale*canvas.getHeight()));
SnapshotParameters spa = new SnapshotParameters();
spa.setTransform(Transform.scale(pixelScale, pixelScale));
return canvas.snapshot(spa, writableImage);
}
I need to find a way to "upsample" text from 72dpi (screen) to 300dpi (print) for rendered client generated text. This is a true WYSIWYG application and we're expecting a ton of traffic so client side rendering is a requirement. Our application has several fonts, font sizes, colors, alignments the user can modify in a textarea. The question is how to convert 72dpi to 300dpi. We have the editior complete, we just need to make 300dpi versions of the textarea.
MY IDEA
1) Get textarea and increase the height, width, and font size by 300/72. (if ints are needed on font size I may need to increase the font then down-sample to the height/width)
2) use BitmapUtil.getSnapshot on the textarea to get a rendered version of the text
THE QUESTION
How can I render text inside of a textarea without the component lifecycle? Imagine:
var textArea:TextArea = new TextArea();
textArea.text = "This is a test";
var bmd:BitmapData = textArea.render();
Like Flextras said, width/height has nothing to do with DPI, unless you actually zoom into the application by 4.16X. If your application all has vector based graphics, it shouldn't be a problem. Plus, the concept of DPI is lost in any web application until you're trying to save/print a bitmap.
It's definitely possible, but you'll have to figure it on your own.
To ask a question another way, it is possible to create a TextArea in
memory which I can use the BitmapUtil.getSnapshot() function to
generate a BitmapData object
Technically, all components are in memory. What you want to do, I believe, is render a component without adding it to a container.
We do exactly this for the watermark on Flextras components. Conceptually we created a method to render the instance; like this:
public function render(argInheritingStyles : Object):void{
this.createChildren();
this.childrenCreated();
this.initializationComplete();
this.inheritingStyles = argInheritingStyles;
this.commitProperties();
this.measure();
this.height = this.measuredHeight;
this.width = this.measuredWidth;
this.updateDisplayList(this.unscaledWidth,this.unscaledHeight);
}
The method must be explicitly called. Then you can use the 'standard' procedure for turning the component into a bitmap. I think we use a Label; but the same approach should work on any given component.
Here is the final method I used to solve the problem of creating a printable version of the text and style of a Spark TextArea component. I ended up placing the custom component TextAreaRenderer (see below) in the MXML and setting the visibility to false. Then using the reference to this component to process any text field (renderObject) and get back a BitmapData object.
public class TextAreaRenderer extends TextArea implements IAssetRenderer
{
public function render(renderObject:Object, dpi:int = 300):BitmapData{
// CAST THE OBJECT
//.................
var userTextArea:TextArea = TextArea(renderObject);
// SCALE IS THE DIVISION OF THE NEW DPI OVER THE SCREEN DPI 72
//............................................................
var scale:Number = dpi / 72;
// COPY THE USER'S TEXT AREA INTO THE OFFSCREEN TEXT AREA
//.......................................................
this.text = userTextArea.text; // the actual text
this.height = Math.floor(userTextArea.height * scale); // scaled height
this.width = Math.floor(userTextArea.width * scale); // scaled width
// GET THE LAYOUT FORMATS AND COPY TO OFFSCREEN
// - the user's format = userTextAreaLayoutFormat
// - the hidden format = thisLayoutFormat
//...............................................
var editableLayoutProperties:Array = ['fontSize', 'fontFamily', 'fontWeight', 'fontStyle', 'textAlign', 'textDecoration', 'color']
userTextArea.selectAll();
var userTextAreaLayoutFormat:TextLayoutFormat = userTextArea.getFormatOfRange();
this.selectAll();
var thisLayoutFormat:TextLayoutFormat = this.getFormatOfRange();
for each(var prop:String in editableLayoutProperties){
thisLayoutFormat[prop] = userTextAreaLayoutFormat[prop];
}
// SCALE THE FONT SIZE
//....................
thisLayoutFormat.fontSize = thisLayoutFormat.fontSize * scale;
// SET THE FORMAT BACK IN THE TEXT BOX
//...................................
this.setFormatOfRange(thisLayoutFormat);
// REDRAW THE OFFSCREEN
// RETURN THE BITMAP DATA
//.......................
this.validateNow();
return BitmapUtil.getSnapshot(this);
}
}
Then calling the TextAreaRenderer after the text area is changed to get a scaled up bitmap.
// COPY THE DATA INTO THE OFFSCREEN COMPONENT
//............................................
var renderableComponent:IAssetRenderer = view.offScreenTextArea;
return renderableComponent.render(userTextArea, 300);
Thanks to the advice from www.Flextras.com for working through the issue with me.
I have an image loaded from an url and added to canvas as child. Then I am drag and dropping another image on it which also uses the senocular transform so the image can be transformed on the canvas. I have coded in such way that the transform handles shows up only after it's dropped on canvas. The image shows up correctly. But I am trying to save the result image (that is the main image and the dropped image on top of it), I only end up with the main image that was loaded earlier. The dropped image doesn't show up.
Below is the code for handleDrop() that is fired on dragDrop event and prepares the final image. What am I doing wrong?
var dragInitiator:IUIComponent = dragEvent.dragInitiator;
var dropTarget:IUIComponent = dragEvent.currentTarget as IUIComponent;
var tool:TransformTool = new TransformTool(new ControlSetStandard());
var items:String = dragEvent.dragSource.dataForFormat("items") as String;
var img:Image = new Image();
img.x=50;
img.y=50;
img.width=55;
img.height=55;
img.source=items.toString();
var bitmap:Bitmap= Bitmap(img.content);
var tool:TransformTool = new TransformTool(new ControlSetStandard());
var component:UIComponent = new UIComponent( );
tool.target = img;
tool.x=myCanvas.x;
tool.y=myCanvas.y;
addElement(component);
myCanvas.addChild(img);
img.z=myCanvas.z+1;
component.addChild(tool);
original=new BitmapData(bmd.width,bmd.height,true,0x000000FF);
original.draw(myCanvas);
Just because you added the image to the canvas doesn't mean it has drawn already. Either listen for the updateComplete event on the image or do a callLater to a function that then draws the bitmap.
Well, the problem may be a simple one but I can't figure it out. I have an image loaded into BitmapData. now I want to take text from a textinput and put it on the BitmapData. Basically it's drawing a text on the BitmapData and get the result as another BitmapData that will consist of the original BitmapData with the text drawn over it on a specified position. What's the best way to achieve this in flex?
To put the text inside a bitmap you can do:
var channelName:TextField = new TextField();
channelName.textColor=0x000000;
channelName.antiAliasType = AntiAliasType.NORMAL;
channelName.alpha=1.0;
var txtFormat:TextFormat = new TextFormat("SansSerif",14,0x000000,true);
channelName.setTextFormat(txtFormat);
var bitmapdata:BitmapData = new BitmapData(
channelName.width, channelName.height, true, 0x000000);
bitmapdata.draw(channelName);
You can't draw over bitmapdata per say, but you could compose it from the data. Since you have BitmapData, it's easy enough to change it to a bitmap (var bitmap:Bitmap = new Bitmap(bitmapData);) and then add it as source for an image.
Now that you have an actual image on the stage, you can now add text above that using what you like (text, label, textarea, etc) and then you can do a Bitmap.draw over the dimensions of the image to get the pixel information back into a BitmapData (under Bitmap.bitmapData).