kineticjs image backgrounds not transparent - transparency

I have some images that are .png's with transparent backgrounds however, when they are added to the stage they have white backgrounds. Am i missing a trick here?
Each image is added like so:
var layer = new Kinetic.Layer();
var book = new Image();
book.onload=function () {
bookImg = new Kinetic.Image ({ x: 885, y: 780, offset: [85.5, 106], image:book, name:book, opacity: 0, /*scale:{x:0.5, y:0.5}*/ });
layer.add(bookImg);
stage.add(layer);
}
book.src = "images/book.png";
is it that the layer itself is what's creating the white background?
a little confused!

Cant it be that you have to set the background to transparent? Not only the picture itself but the image-object containing the image. Maybe the layer aswell.

You shouldn't need to set the opacity on a Kinetic.Image() object. If you want it to be invisible, either initially or after being placed, simply use hide() (and subsequently show() to re-show it). Or set visible to false in the parameters. The minimum needed to place an image on the stage looks like this:
var image = new Kinetic.Image({
x: 0,
y: 0,
image: imageObj,
width: 300,
height: 120
});
layer.add(image);
layer.draw();
This assumes your layer has already been added to a Kinetic.Stage() and the image has loaded ( imageObj.onload = function(){} ). Including a name is fine, the offset and opacity (and even scale) are valid key/value pairs for parameters but not really necessary when creating the image. These can always be set after the image has been added to the layer as well (using one of the many setters in the KineticJS library).
I'd try using a minimalist approach to see if the image shows up as intended first, then go from there.

Related

Konva JS why scenefunc context.circle is not working?

I am trying to create custom share a circle and BIN inside that circle to use as button.
but context.circle is not working in documention they mentioned, rect, circle, text.. we can use with custom shape.
Please letme know what is the issue, is it bug or something i am missing.
var rect = new Konva.Shape({
x: 10,
y: 20,
fill: '#00D2FF',
radius: 10,
sceneFunc: function (context, shape) {
context.beginPath();
context.circle(0, 0, 5);
context.fillStrokeShape(shape);
},
});
context argument is a wrapper around 2D native canvas context https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D.
You should use its methods to make drawings. In your case you may need context.arc: https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/arc

What is the best way to drag a transformer by dragging from empty areas in Konvajs?

I'm currently following this guide to select shapes in the stage and put them inside a Transformer.
If possible, I'd like to drag an entire Transformer with all of its content without touching any of the shapes inside.
For example, I have two lines that are far from each other. Both of them are nodes inside a Transformer and can be dragged as long as I click one of those 2 lines. However, if I tried to drag from any of the empty area inside the Transformer nothing would happen (or the transformer would reset, depending on the code).
I'm thinking of adding a transparent Rect (this Rect will always have the same size as the Transformer) to the Transformer and then add any other shape that I want inside the Transformer. Since both the Rect and the Transformer have the same size, I could easily drag the entire Transformer from any "empty area" where my other shapes are not located.
I'm not sure if this is the correct/efficient way to do it. How should I tackle this issue to obtain the best outcome?
There is an experimental property shouldOverdrawWholeArea for Konva.Transformer. It is not in the docs yet.
If you set it to true the whole transformer area will be available for drag.
But if you have a transformer on top of other shapes, then shapes will be not listening for regular events (such as click, touchstart etc). Because the transformer rectangle will overdraw hit area of attached shapes. Even will start working as soon, as you remove such a transformer from them.
const stage = new Konva.Stage({
container: 'container',
width: window.innerWidth - 20,
height: window.innerHeight - 20
});
const layer = new Konva.Layer();
stage.add(layer);
const shape1 = new Konva.Circle({
x: 70,
y: 70,
radius: 50,
fill: 'green'
});
layer.add(shape1);
const shape2 = shape1.clone({
x: 190,
y: 90
})
layer.add(shape2);
const tr = new Konva.Transformer({
nodes: [shape1, shape2],
shouldOverdrawWholeArea: true
});
layer.add(tr);
layer.draw();
<script src="https://unpkg.com/konva#7.0.3/konva.min.js"></script>
<div id="container"></div>

Konvajs custom shapes and transformers

What I am trying to achieve is showing the transformer around the custom shape itself. I took the code directly from the API docs for creating the custom shape and adding the transformer. The transformer works great for rectangles, circles, etc but for custom shapes, it doesn't seem to appear properly.
Here is a link to a demo app with the issue with custom shapes and transformer:
https://jsfiddle.net/5zpua740/
var stage = new Konva.Stage({
container: 'container',
width: window.innerWidth,
height: window.innerHeight
});
var layer = new Konva.Layer();
/*
* create a triangle shape by defining a
* drawing function which draws a triangle
*/
var triangle = new Konva.Shape({
sceneFunc: function (context) {
context.beginPath();
context.moveTo(120, 150);
context.lineTo(320, 180);
context.quadraticCurveTo(250, 200, 360, 270);
context.closePath();
// Konva specific method
context.fillStrokeShape(this);
},
fill: '#00D2FF',
stroke: 'black',
strokeWidth: 4,
draggable: true
});
// add the triangle shape to the layer
layer.add(triangle);
// add the layer to the stage
stage.add(layer);
stage.on('click', function (e) {
// if click on empty area - remove all transformers
if (e.target === stage) {
stage.find('Transformer').destroy();
layer.draw();
return;
}
// remove old transformers
// TODO: we can skip it if current rect is already selected
stage.find('Transformer').destroy();
// create new transformer
var tr = new Konva.Transformer();
layer.add(tr);
tr.attachTo(e.target);
layer.draw();
})
In this sample, you can see that if you click on the object, the transformer appears in the corner. You can still use it to manipulate the object but it's not around the object itself.
Any help appreciated! Thanks in advance.
Konva can't detect bounding box of a custom shape. But we can simply help it. We just need to define a method getSelfRect.
The method should return bounding box of a shape without transforming applied (like the shape has no rotation, no scaling and placed in x =0, y=0).
We can do this by just looking at sceneFunc:
triangle.getSelfRect = function() {
return {
// sceneFunc started from moving to 120, 150 point
// so it is our top left point
x: 120,
y: 150,
// the bottom right point finished with quadraticCurveTo
// I will use the coordinates to calculate size of the shape
width: 360 - 120,
height: 270 - 150
};
}
Demo: http://jsbin.com/lazuhowezi/2/edit?js,output

Trigger resizable in jasmine [duplicate]

I have a div element which is made jquery Resizable. It has alsoResize option set, so other elements resize simultaneously.
What I want to do, is to set size of this Resizable div element programmatically in such way, that all Resizable logic is triggered (especially this alsoResize option is taken into account).
How can I achieve that?
Update: It looks like the internals of jQuery UI have changed dramatically since I answered this and firing the event no longer works.
There's no direct way to fire the event anymore because the resizable plugin has been fundamentally changed. It resizes as the mouse is dragged rather than syncing items up at the end. This happens by it listening for the internal resize propagation event for resizable plugins which is now fired by the _mouseDrag handler. But it depends on variables set along the way, so just firing that even internally won't help.
This means even overriding it is messy at best. I'd recommend just manually resizing the alsoResize elements directly, independent of the UI widget altogether if that's possible.
But for fun let's say it isn't. The problem is that the internals of the plugin set various properties relating to previous and current mouse position in order to know how much to resize by. We can abuse use that to add a method to the widget, like this:
$.widget("ui.resizable", $.ui.resizable, {
resizeTo: function(newSize) {
var start = new $.Event("mousedown", { pageX: 0, pageY: 0 });
this._mouseStart(start);
this.axis = 'se';
var end = new $.Event("mouseup", {
pageX: newSize.width - this.originalSize.width,
pageY: newSize.height - this.originalSize.height
});
this._mouseDrag(end);
this._mouseStop(end);
}
});
This is just creating the mouse events that the resizable widget is looking for and firing those. If you wanted to do something like resizeBy it'd be an even simpler end since all we care about is the delta:
var end = $.Event("mouseup", { pageX: newSize.width, pageY: newSize.height });
You'd call the $.widget() method after jQuery UI and before creating your .resizable() instances and they'll all have a resizeTo method. That part doesn't change, it's just:
$(".selector").resizable({ alsoResize: ".other-selector" });
Then to resize, you'd call that new resizeTo method like this:
$(".selector").resizable("resizeTo", { height: 100, width: 200 });
This would act as if you instantly dragged it to that size. There are of course a few gotchas here:
The "se" axis is assuming you want resize by the bottom right - I picked this because it's by far the most common scenario, but you could just make it a parameter.
We're hooking into the internal events a bit, but I'm intentionally using as few internal implementation details as possible, so that this is less likely to break in the future.
It could absolutely break in future versions of jQuery UI, I've only tried to minimize the chances of that.
You can play with it in action with a fiddle here and the resizeBy version here.
Original answer:
You can do this:
$(".selector").trigger("resize");
alsoResize internally rigs up a handler to the resize event, so you just need to invoke that :)
You can trigger the bars programmatically. For example, to trigger the east-west resize event:
var elem =... // Your ui-resizable element
var eastbar = elem.find(".ui-resizable-handle.ui-resizable-e").first();
var pageX = eastbar.offset().left;
var pageY = eastbar.offset().top;
(eastbar.trigger("mouseover")
.trigger({ type: "mousedown", which: 1, pageX: pageX, pageY: pageY })
.trigger({ type: "mousemove", which: 1, pageX: pageX - 1, pageY: pageY })
.trigger({ type: "mousemove", which: 1, pageX: pageX, pageY: pageY })
.trigger({ type: "mouseup", which: 1, pageX: pageX, pageY: pageY }));
I am doing a 1px left followed by 1px right movement on the east bar handle.
To perform a full size, you can target .ui-resizable-handle.ui-resizable-se if you have east and south resize bars.
I needed the same thing for tests. Similar questions have only one promising answer https://stackoverflow.com/a/17099382/1235394, but it requires additional setup, so I ended with my own solution.
I have an element with resizable right edge
$nameHeader.resizable({handles: 'e', ... });
and I needed to trigger all callbacks during the test in order to resize all elements properly. The key part of test code:
var $nameHeader = $list.find('.list-header .name'),
$nameCell = $list.find('.list-body .name');
ok($nameHeader.hasClass('ui-resizable'), 'Name header should be resizable');
equal($nameCell.outerWidth(), 300, 'Initial width of Name column');
// retrieve instance of resizable widget
var instance = $nameHeader.data('ui-resizable'),
position = $nameHeader.position(),
width = $nameHeader.outerWidth();
ok(instance, 'Instance of resizable widget should exist');
// mouseover initializes instance.axis to 'e'
instance._handles.trigger('mouseover');
// start dragging, fires `start` callback
instance._mouseStart({pageX: position.left + width, pageY: position.top});
// drag 50px to the right, fires `resize` callback
instance._mouseDrag({pageX: position.left + width + 50, pageY: position.top});
// stop dragging, fires `stop` callback
instance._mouseStop({pageX: position.left + width + 50, pageY: position.top});
// ensure width of linked element is changed after resizing
equal($nameCell.outerWidth(), 350, 'Name column width should change');
Of course this code is brittle and may break when widget implementation changes.
Hack Disclaimer (tested on jQuery 1.12.4):
This basically waits for the dialog to be opened and then increments by 1px (which forces the resize() event) and then decrements by 1px (to regain original size)
just say this in the dialog open event handler:
$(this)
.dialog("option","width",$(this).dialog("option","width")+1)
.dialog("option","width",$(this).dialog("option","width")-1);
note:
This may not work with show effects (like fadeIn,slideDown etc) as the "resizer" code executes before the dialog is fully rendered.
$(".yourWindow").each(function(e) {
$(this).height($(this).find(".yourContent").height());
});
And the same with the width.

where can i find a thorough description of implementing custom ol.style.Style in openlayers 3?

I've read through the source, and looked at the examples but haven't found the answer yet.
I need to style the image that appears on the modify overlay beneath the mouse cursor.
i'm using a custom style function to add midpoints and custom endpoints to the layer used by ol.interaction.Modify. ol.interaction.Modify is applying styling to a point near the mouse cursor to indicate that the feature can be modified. This is great except the cursor styling falls beneath the custom endpoints. i can't find a way to alter the z-index.
so, i'm answering my question for myself. i guess that's what makes the internet wonderful. i'm not a dog.
// we'd normally pass feature & resolution parameters to the function, but we're going to
// make this dynamic, so we'll return a style function for later use which will take those params.
DynamicStyleFunction = ( function( /* no feat/res yet!*/ ) {
/**
you really only get style are rendered upon simple geometries, not features. features are made of different geometry types, and styleFunctions are passed a feature that has its geometries rendered. in terms of styling vector geometries, you have only a few options. side note: if there's some feature you expect to see on the the map and it's not showing up, you probably haven't properly styled it. Or, maybe it hasn't been put it in a collection that is included in the source layer... which is a hiccup for a different day.
*/
// for any geometry that you want to be rendered, you'll want a style.
var styles = {};
var s = styles;
/**
an ol.layer.Vector or FeatureOverlay, renders those features in its source by applying Styles made of Strokes, Fills, and Images (made of strokes and fills) on top of the simple geometries which make up the features
Stroke styles get applied to ol.geom.GeometryType.LINE_STRING
MULTI_LINE_STRING can get different styling if you want
*/
var strokeLinesWhite = new ol.style.Stroke({
color: [255, 255, 255, 1], // white
width: 5,
})
var whiteLineStyle new ol.style.Style({
stroke: strokeLinesWhite
})
styles[ol.geom.GeometryType.LINE_STRING] = whiteLineStyle
/**
Polygon styles get applied to ol.geom.GeometryType.POLYGON
Polygons are gonna get filled. They also have Lines... so they can take stroke
*/
var fillPolygonBlue = new ol.style.Style({
fill: new ol.style.Fill({
color: [0, 153, 255, 1], // blue
})
})
var whiteOutlinedBluePolygon = new ol.style.Style({
stroke: strokeLinesWhite,
fill: fillPolygonBlue,
})
styles[ol.geom.GeometryType.POLYGON] = fillPolygonBlue
/**
Circle styles get applied to ol.geom.GeometryType.POINT
They're made with a radius and a fill, and the edge gets stroked...
*/
var smallRedCircleStyle = new ol.style.Style({
image: new ol.style.Circle({
radius: 5,
fill: new ol.style.Fill({
color: '#FF0000', // red... but i had to look it up
})
})
})
var whiteBigCircleWithBlueBorderStyle = new ol.style.Style({
image: new ol.style.Circle({
radius: 10,
fill: new ol.style.Fill({
color: '#FFFFFF' // i guessed it
})
}),
stroke: new.ol.style.Stroke({
color: '#0000FF', // blue
width: 5
})
})
// render all points as small red circles
styles[ol.geom.GeometryType.POINT] = smallRedCircleStyle
// if you pass an array as the style argument, every rendering of the feature will apply every defined style style rendered with the geometry as the argument. that can be a whole lot of rendering in a FeatureOverlay...
smallRedCircleStyle.setZIndex(Infinity)
whiteBigCircleWithBlueBorderStyle.setZIndex(Infinity -1) // that prob wouldn't work, but i hope it's instructive that you can tinker with styles
// so...
var bullseyePointStyle = [ smallRedCircleStyle, whiteBigCircleWithBlueBorderStyle ];
return function dynamicStyleFunction (feature, resolution){
// this is the actual function getting invoked on each function call
// do whatever you want with the feature/resolution.
if (Array.indexOf(feature.getKeys('thisIsOurBullseyeNode') > -1) {
return bullseyePointStyle
} else if (feature.getGeometryName('whiteBlueBox')){
return whiteOutlinedBluePolygon
} else {
return styles[feature.getGeometryName()]
}
}
})()
ol.interaction.Modify, ol.interaction.Select and ol.interaction.Draw take a style argument to change the look of the sketching features.

Resources