I made a preview dialog containing fabric.js canvas. It can be opened by clicking on "Preview" button for each item in a list. Each item in a list is associated with function which draws preview on this canvas. The preview canvas has width/height 90% of the browser screen. Is this a way to center this drawing on the fabric.js canvas (both horizontally and vertically)? Also is there a way to scale it so that it fits within canvas no matter what display size user has? The sizes of drawings are known. But I can't find how I can get canvas width/height from fabric.js and in what measures.
Tried to find the answer in fabric.js docs. I need to get fabric.js canvas width and height.
Related
I have a canvas whose height and width attributes are not mentioned during creation. I update the height and width of it through javascript so that it always fills the viewport height and width. When I use a jpg for the canvas background, it works fine. But when I use a svg, I find that it gets clipped to the default canvas dimension ( 300px x 150px ). But if I set the height and width of the canvas as attributes directly in the tag, then the svg fills the entire canvas properly. Why does SVG behave this way and how can I fix i?
I know fabricjs can play Video and sprite sheet, But I have a lot of gif files, can I play these gif directly with fabricjs? I am not able to find method in Fabricjs website.
According to specs about the Canvas 2DRenderingContext drawImage method,
Specifically, when a CanvasImageSource object represents an animated image in an
HTMLImageElement, the user agent must use the default image of the animation (the one
that the format defines is to be used when animation is not supported or is
disabled), or, if there is no such image, the first frame of the animation, when
rendering the image for CanvasRenderingContext2D APIs.
This means that only the first frame of our animated canvas will be drawn on the canvas.
This is because we don't have any control on animations inside an img tag.
And fabricjs is based on canvas API, thus regulated by the same rules.
The solution is you need to parse all the still-images from your animated gif and to export it as a sprite-sheet. You can then easily animate it in fabricjs thanks to the sprite class.
I have my my FabricJS canvas inside a container with a fixed height/width in pixels. On the side I have a dropdown to change the canvas size to various presets. What I would like to do is automatically zoom out whenever I select a size that is either taller and/or wider than the container. So for example, if my container div is 800x600 and I select a canvas size of 1024x768, I want to zoom out so that the entire canvas is still visible. Conversely, I'd like to zoom in up to 100% if I select a smaller size (e.g. 200x200).
I found this example of zooming, but no matter how much you zoom out, the canvas size appears to stay the same. See screenshot:
How can I accomplish this?
As you can see here, the area with the thin red border is the canvas container. The white box is the canvas.
You can use the canvas.setDimensions function to accomplish this. You pass two arguments to it; the first is an object specifying the height and width to change the canvas to and the second indicates whether to change the css, the actual size of the canvas, or both.
For example,canvas.setDimensions({width: 750, height: 750}, {backstoreOnly: true} will set the actual size of the canvas to be 750x750, regardless of the display.
canvas.setDimensions({width: '750px', height: '750px'}, {cssOnly: true}) will set the display size of the canvas to be 750x750, regardless of the actual size.
I'm not 100% sure whether the width or height require a px after it for css or for backstore, but that's a pretty simple thing to check. Also, if no argument is passed for the second parameter, it will change both.
I have a map which pulls in GeoJSON polygons and points.
I represent these using the standard Leaflet methods to create SVG and html markers respectively.
To get an idea: http://i.imgur.com/GSJSZIc.jpg
SVG = blue, markers = green.
Leaflet creates 'panes', div.leaflet-overlay-pane for the SVG, and div.leaflet-marker-pane for markers. The leaflet-marker-pane (bordered in red) covers half the viewport and has a higher z-index then the leaflet-overlay-pane, thereby making the SVG polys under it unclickable.
If I set the zindex of the overlay pane to be less than the marker pane, all the markers are unclickable as the overlay pane covers the whole view port.
I've read some things in the Leaflet Github issues about createPane(), but so far haven't seen it working. Should/will this be something which fixes this problem? ie, puy all markers and SVG polys in the same pane/div.
For the time being I've set the marker pane to be 1px x 1px. This seems to work fine, leading me to ask, why would the marker pane ever be set to half the viewport size?
you have to add your svg into leaflet-marker-pane, for that just use option 'pane' when you add your SVG to the map
L.svgOverlay(svgOverlayElement, map.getBounds(), { pane: 'markerPane' }).addTo(map)
I'd like to make my SVG images interactive, with a zoom box that can be moved around by hovering or clicking the mouse in certain areas. Can this be done in a single SVG file, so that I can embed this interactive SVG image in a pdf?
You mean like this? Zoom and Pan