I have an SVG asset of a map, in which I have to change the color of some cities depending on the results of a network call. On the web, one normally would add a class to each path, give it some CSS, and toggle that class using JavaScript.
How can I achieve the same effect in flutter?
This can be done with the new version of jovial_svg. It supports embedded stylesheets, so you can use CSS exactly as suggested. Of course, you'd need to re-parse the SVG whenever there's a change, but that's not a big deal here.
Alternately, if it's just one set of cities, you could use SVG's currentColor, and set that value in the appropriate ScalableImage factory. But for your use case, CSS seems like the better way to go.
NOTE: At this exact moment, CSS support is in pre-release, but it should be formally released as 1.1.4 within a couple of days. In the meantime, see https://pub.dev/packages/jovial_svg/versions/1.1.4-rc.3
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My company USES the html2canvas screenshot framework, but it does not support SVG format and is not friendly to the new CSS properties, such as transform, and the shape of the ellipse can sometimes be inconsistent with the original image.
There is no new open source framework to support these requirements. There is no framework to replace the html2canvas framework with the functionality of the screenshot.
My English is not good, I use the translation, thank you
i have the same problem, but here's the think you should consider:
html2canvas is only support this CSS Property.
the developers themselves say "It's not suitable for production".
But if you still want to use it, you can try to make work around by changing the CSS before render and change it back after render.
Also for the SVG issue, you can use plugin canvg, replace the svg with the canvas that canvg provide before render.
But it's still unstable, the image sometime is off the image.
i suggest to use server side capture with phantomjs, here's the example for that:
var page = require('webpage').create();
page.open('http://github.com/', function() {
page.render('github.png');
phantom.exit();
});
it's quite fast i would say.
Hope it could help.
Firefox addon. I'm porting an existing addon to a restartless one. I have a panel with a lot of UI elements (mostly boxes/description and images) in it, and it is very convenient for me to define the panel elements in an XUL overlay file. I will have lots of bloated js code if I don't.
The panel element (parent) itself is created in code dynamically, and then I use loadOverlay, wait for the 'merged' event and then append the panel element's children from the overlayed document. I also make sure that the elements are cleaned up upon a remove.
However, using overlays will most probably won't pass an AMO review. And some of the reasons I think are :
In most cases overlay elements will cause problems while removing (eg: toolbar buttons remembering their positions etc.)
There are problems with attaching js/css files in an overlay file.
loadOverlay is buggy (496320, 330458)
And here are my inferences :
loadOverlay() API itself is not deprecated - in fact it is 'not frozen and may change later' - which means possibly it will be use-able in future.
The bug that a second overlay load fails, is not applicable in my case, as I don't initialize without an overlay merge.
Using static overlay for preference windows etc. is perfectly acceptable as of now.
The panel in my case behaves a lot like a preference window (which is brought up on demand and cleaned up upon addon removal)
I don't have any js/css attached to the overlay, nor any event listeners for the elements. The overlay is only used to define boxes and description text - nothing more.
So considering these, is it acceptable to use overlays and loadOverlay() for a restartless addon ? If not, is there an alternative ?
About overlays, by checking source code of restartless addon that extend existing addon (like ehh), I see the overlay.xul is auto merged with the existing addon's. So it shouldn't be a problem to use overlay.
I have learned that in iOS 5, properties that are marked with UI_APPEARANCE_SELECTOR can be styled using appearance. Eg [[UINavigationBar appearance] setTintColor:....]. However, I seem not to be able to style all elements. UIButton, for instance, has no properties marked UI_APPEARANCE_SELECTOR, hence I am not able to use the above technique to style it.
My question is: How do I best style elements globally (all appearances in the application), when I cannot use appearance?
Right now I have defined some colors, fonts, shadow offsets etc. that I use many different places in my code. This allows me to change the look and behaviour of a lot of elements, but it still doesn't allow me to style all instances of a certain object with only one line of code.
Edit
In lack of better solutions I have created a number of categories with simple methods as the following:
+ (UIButton *)customLabelWithFrame:(CGRect)frame andText:(NSString *)text;
Also I have found that - in combination with the described categories - stretchable images are nice and useful.
With the above I am able to style in a global-ish manner, however I am not satisfied with the result and I still hope to find a better solution
What about standard subclassing or factory classes, as you mentioned yourself!?
For buttons I'm using factory classes myself.
I think a really nice solution could be the Android way of designing interfaces. Android relies on XML files to define the user interface. As a matter of fact, I'm working on a library that aims to give the projects I'm working on much the same capabilities. It's still a work in progress / experiment and as such really messy code (you have been warned!), but it might give you some ideas.
An example project can be downloaded here: http://dl.dropbox.com/u/6487838/WSLayoutManager.zip
Experiment a bit with the XML files by adding controls. Create custom control classes and instantiate them from the XML file, etc... It's fun stuff :)
Instead of using DisplayFor and EditorFor, I would like to create a more generic ContentFor. In that Html extension it would take into account Metadata values to determine how to render the resulting control. The only piece of the puzzle I am not am to determine is this: Is there a way to determine if I am currently rendering a DisplayTemplate or an EditorTemplate. As a real-world example of this, when rendering a string, for the display version I would like to render it as a , but when rendering the editor version, I would want to render it as a text box.
To better explain, let's say I have two templates called Address.ascx, one in the DisplayTemplates directory and one in the EditorTemplates directory. I would like both of them to use ContentFor to render, but in the display version it renders as a label and in the editor version it renders as a textbox.
Using two ASCX files to call a single file control (which is doable, just do another RenderPartial or DisplayFor/LabelFor) doesn't make sense to me. It breaks the "seperation of concerns". Label displays labels, and Display displays values, it doesn't make sense for a control to try and figure out what way you want it to display.
If you want a use a custom display or label for a property, use the UIHint data Annotation.
[UIHint("MyCustomControlName")]
Then in the DisplayTemplates and EditorTempaltes create a "MyCustomControlName.ascx" file to display that property however you want. Additionally, the ascx controls can read custom Model Metadata and do whatever it is you need done. Example at http://weblogs.asp.net/seanmcalinden/archive/2010/06/11/custom-asp-net-mvc-2-modelmetadataprovider-for-using-custom-view-model-attributes.aspx.
I'm learning to use GWT 2.0 and I'm trying to convert the StockWatcher demo to use the UiBinder. the demo uses stocksFlexTable.getRowFormatter().addStyleName(0, "watchListHeader"); to add styles, but when I add <ui:style> to my XML and move my CSS I can't seem to figure out how to make the style work because there is no stocksFlexTable.getRowFormatter().addStyle(). Does <ui:style> just not work with FlexTables?
I tried to deal with it as well with no success. I believe though that dynamic widgets such as FlexTable are not fully supported for obvious reasons - i.e. you can't preset the style for the nth row when you don't really know how many rows the table will hold. Also, providing some arbitrary way to do it for the first only, or odd rows etc. would require more expressive power than what the GWT developers seem keen to offer (they try to stick close to XHTML) and i believe they state at the wiki at somepoint that declarative syntax is by no means a templating language. Anyway, you can always experiment with #UiFactory and #UiField(provided=true) to try and stick close to GWT recommendations. But still, you ll have to set any such values programmatically.
I had success by removing the section completely and moving all of the css for the FlexTable into the application css file.