I am having an issue with jetpack compose canvas when using #Preview, I would like to display all the content to fill the canvas in the preview but it doesn't currently.
I am setting 375dp width and then a Rect with 375f, I understand that dp is different than just float, but how can I set the width so the green rect fills the canvas without using canvas.width for example as the rect width?
When drawing on Canvas you're operating with pixels, not Dp. onDraw is called on DrawScope, and it has size property which is already converted to pixels:
Canvas(Modifier) {
drawRect(color = Color.Green, size = size)
}
Also DrawScope is inherited from Density, so you can convert any Dp to pixels with 375.toDp().
Related
I am trying to resize elements in canavas using konva js plugin concept. But the resized width and height are not saved to database. My actual height width are not being replaced by resized height widths for any of the elements whether a image,layer,stage
Do you change sizes with Konva.Transformer (https://konvajs.org/docs/vue/Transformer.html)?
If so - Transformer tool doesn't change width and height directly. Instead, it is changing scaleX and scaleY of a node. So you just need to save that attrs too into a database or change width/height to match new scaling:
const newWidth = rectangle.width() * rectangle.scaleX();
// set new width
rectangle.width(newWidth);
// reset scale:
rectangle.scaleX(1);
When I am using QScatterSeries, I can very easily draw point at (x, y). However, instead of points I would like to draw short lines, like in the figure below. How can I get about doing so?
I tried using RectangleMarker, but it just draws a fat square. I would prefer a thin line about 2px wide and 20px in height.
Is there a way I can add custom marker shapes?
Here are the code and the settings I use to transform my points into lines :
//create scatter series to draw point
m_pSeries1 = new QtCharts::QScatterSeries();
m_pSeries1->setName("trig");
m_pSeries1->setMarkerSize(100.0);
//draw a thin rectangle (50 to 50)
QPainterPath linePath;
linePath.moveTo(50, 0);
linePath.lineTo(50, 100);
linePath.closeSubpath();
//adapt the size of the image with the size of your rectangle
QImage line1(100, 100, QImage::Format_ARGB32);
line1.fill(Qt::transparent);
QPainter painter1(&line1);
painter1.setRenderHint(QPainter::Antialiasing);
painter1.setPen(QColor(0, 0, 0));
painter1.setBrush(painter1.pen().color());
painter1.drawPath(linePath);
//attach your image of rectangle to your series
m_pSeries1->setBrush(line1);
m_pSeries1->setPen(QColor(Qt::transparent));
//then use the classic QtChart pipeline...
You can play the marker size, the dimension of the image and the drawing pattern in the painter to adapt the size and shape of the rectangle to obtain a line.
In the picture, it's the black line. As you can see you can repeat the process for other series.
Keep in mind that you cannot use the openGL acceleration:
m_pSeries0->setUseOpenGL(true);
My work is based on the QtCharts/QScatterSeries example : QScatterSeries example
Hope it will help you.
Florian
I was created a new project using flash cc html5 canvas and created a movieclip with 200px width and 200px height. I can able to get the properties using this.mc.nominalBounds;. And I tried this.mc.getBounds ();
But it returns null. setBounds also not seems to work.
The setBounds method is for putting a custom bounds on something, or defining it when it can not be determined (like using the Graphics classes). Fortunately, all symbols from Flash CC come with nominalBounds, which is the combined, untransformed size of the symbol.
Using that, you can set the scaleX and scaleY properties to size up and down your content. If you want it to be a specific width, just use the nominalBounds to determine a new scale.
For example, if the clip is 200x200, and you want it to be 400x400, then:
var scale = newWidth / nominalBounds.width;
clip.scaleX = clip.scaleY = scale;
Hope that helps!
I am doing DoubleAnimation of the Width property of a Canvas. I want to shrink the canvas to 1/5 th of the size.
var widthAnimation = new DoubleAnimation();
widthAnimation.Duration = new TimeSpan(0,0,1);
StoryBoard.SetTarget(widthAnimation, Canvas1);
StoryBoard.SetTargetProperty(widthAnimation, new PropertyPath("Width"));
widthAnimation.From = Canvas1.Width;
widthAnimation.To = Canvas1.Width * .2;
StoryBoard stb = new StoryBoard();
stb.Children.Add(widthAnimation);
stb.Begin();
Somehow, the above animation does not shrink the size to 1/5th. Instead, it enlarges the canvas. Any clues why the animation is doing something funny?
The canvas was wrapped in a viewbox. The Viewbox size was fixed, while the canvas within it shrinked. The text expanded. Not sure why. But, I fixed the problem by applying the animation to the Viewbox rather than the Canvas. And it works all fine now.
I have an image area in my application with width:530px and height:510px. I want to place images in that area but the images comes in different different sizes. how to crop or scale the image without losing aspect ratio to fill that area. Is there any native methods available in winjs?
You have a few options for that.
One is to use the ViewBox control that WinJS provides you. The ViewBox can only have a single child (so you would have your tag as its only child perhaps or a div that contains your img) and it will scale that child (using CSS transforms) up to fit into its container (without changing the aspect ratio). It's pretty slick.
Another option is to set the image as the CSS background-image property of a container (such as a div) and set the background-size property to contain. This will stretch the image up to the size of the container.
A final option that you have to resort to if your case is a bit special is not such a bad option after all. In the updateLayout method of your page, you can refer to the element and explicitly set its CSS properties to fit. At that point you'll know all about the layout and can easily do the math to figure out what size image should be. Here's some code from one of my projects where I do this. Notice that I'm comparing the aspect ratio of the screen and the image to determine whether I should size to the width or the height. Unlike your situation (I'm guessing), my code makes sure the image fills the screen and excess is clipped. I'm guessing you want your img to be contained.
function setImagePosition() {
var img = q(".viewCamera #viewport img");
if (outerWidth/outerHeight > img.naturalWidth/img.naturalHeight) {
img.style.width = format("{0}px", outerWidth);
img.style.height = "";
img.style.top = format("{0}px", (outerHeight - img.clientHeight) / 2);
img.style.left = "0px";
} else {
img.style.width = "";
img.style.height = format("{0}px", outerHeight);
img.style.top = "0px";
img.style.left = format("{0}px", (outerWidth - img.clientWidth) / 2);
}
}
Hope that helps!
Are you referring to scaling HTML images? If so, you can set either one, width or height. Whichever you set, the other will scale and keep image aspect ratio.