I'm trying to get a Gtk::Spinner object to display while calculations are in progress but nothing appears to be happening. The snippet of code looks like...
{
Gtk::Spinner spinner;
spinner.start ();
// do some work...
spinner.stop ();
}
I'd have thought the spinner needed to know which dialogue it appears over but I can't see any way of feeding that into the object. Does anyone know where I could find a worked example? I can find the Gtk documentation in many places, but that isn't helping much.
In short, here is a quick checklist if Gtk::Spinner is not appearing on screen:
Make sure librsvg is installed.
Check if your currently active Gtk theme has an image file with base name "process-working-symbolic" (e.g. /path/to/your/theme/icons/scalable-up-to-32/status/process-working-symbolic.svg).
In your app code: Make sure you added the spinner object to some parent widget / container: vbox.pack_start(spinner, Gtk::PACK_SHRINK);
In your app code: Ensure all widgets are actually made visible: show_all_children();
In your app code: Finally you need to call spinner.start() for the widget to actually appear and spin on screen.
In detail:
The actual Gtk spinner widget code (see function gtk_spinner_class_init() in gtkspinner.c) is not doing any drawing on its own. In fact its code is very little. All it does is adding CSS code to the gtk widget:
it assigns the CSS class "spinner" to the widget
and it automatically adds and removes the CSS pseudo-class "checked" whenever the widget's boolean gtk property "active" changes.
So the actual look (icon) and the animation is defined by your current theme's CSS file. E.g. in Gtk's default theme's gtk-contained.css file you find the following:
spinner {
background: none;
opacity: 0;
-gtk-icon-source: -gtk-icontheme("process-working-symbolic");
};
Which means it will automatically search for an appropriate image file with base name "process-working-symbolic" in the theme's "icons" directory tree. And the actual spinning animation is defined in the same CSS file by this:
spinner:checked {
opacity: 1;
animation: spin 1s linear infinite;
};
In most other themes these CSS code portions for the spinner widget are pretty much identical.
Now here is a common problem with this: in most themes the spinner image is an SVG file (e.g. typically "process-working-symbolic.svg"), but the stock Gdk pixbuf loaders do not support the SVG format at all. They support a variety of other image file formats, but for actually allowing Gdk/Gtk to load .svg files you need to install a third-party pixbuf loader capable to do so like librsvg.
Alternative:
In case you cannot or don't want to bother to install an SVG capable Gdk pixbuf loader like librsvg, then you can also simply add image file(s) with the same base name, but in another file format like "process-working-symbolic.png" to your theme's icons directory tree. So either draw or download some spinner picture then scale it and place them several times to the resolutions listed in your theme's "icons" directory, e.g.:
/THEMEDIR/icons/8x8/status/process-working-symbolic.png
/THEMEDIR/icons/16x16/status/process-working-symbolic.png
/THEMEDIR/icons/22x22/status/process-working-symbolic.png
/THEMEDIR/icons/24x24/status/process-working-symbolic.png
/THEMEDIR/icons/32x32/status/process-working-symbolic.png
/THEMEDIR/icons/64x64/status/process-working-symbolic.png
/THEMEDIR/icons/256x256/status/process-working-symbolic.png
/THEMEDIR/icons/512x512/status/process-working-symbolic.png
Also you should know: Whenever you do spinner.start() the spinner icon immediately appears on screen, but even on a decent machine it typically takes almost a second before the spinner starts its animation.
Did you call
spinner.show ();
and add it to some window?
Moreover, your calculations may block the UI, so it is not updated. Call
while (Gtk::Main::events_pending ())
Gtk::Main::iteration ();
once in a while.
To change the mouse cursor to "busy" you can do the following:
Glib::RefPtr<Gdk::Window> window = dialog.get_window();
if(window) {
window->set_cursor(Gdk::Cursor(Gdk::WATCH));
Gdk::flush();
}
To change it back, do
window->set_cursor();
instead.
Disclaimer: I usually work with GTK in C, and have translated this on the fly...
Related
I want to modify GtkFileChooser to view just a specific dir.
Is there any configuration to apply this limitation?
Or if I must manipulate the source code of GTK+, where should I modify?
There is currently no API, and no effort is being spent in trying to sandbox the file selection widget — sandboxing the whole application is, instead, a much bigger priority, see for instance Flatpak and Bubblewrap.
Modifying the GtkFileChooserWidget is not for the faint of heart; you'll have to change the way the widget determines the current directory, and navigates through the parent directories, both from a user interaction standpoint and from an API standpoint.
You'll need to modify:
gtkfilechooserwidget.c — the main file selection widget
gtkfilesystemmodel.c — a GtkTreeModel implementation mapping the file system
gtkpathbar.c — the path bar at the top of the file selection widget
gtkplacessidebar.c — the side bar at the left of the file selection widget
This is probably on of the most complex sites inside the GTK+ code base, alongside with GtkTreeView, GtkMenu, and GtkTextView.
I am working with leaflet api.I can draw rectangles and polygons.I have bound the popup with every rectangle and polygon.When i click on drawn shape, popup opens(leaflet functionality).Popup contains some html(image).
As i am working on a demo application, i am wiling to try the fancebox plugin.
Means, when i click on drawn shape, instead of popup, i want to open up that image using fancybox.
Can i do that using simple method like using another function instead of .bindpopup.
Working Script (image loaded using fance box when we click on popup)
e.layer.bindPopup("<a class='fancybox' rel='group' href=''><img /></a>");
I can understand there must be some other javascript function to do it.
If there is some way to do it please let me know, as i am new to leaflet didn't have enough mental power to understand it yet but i hope i will....
Thanks for your time :)
I would just do e.layer.on('click', function() { //do fancybox init, perhaps like $(body).append("<a class='fancybox' rel='group' href=''><img /></a>")})
Although it makes a lot more performance sense to bind that event on the L.FeatureGroup holding all the shapes instead of one by one.
I want execute some logic after the moment when widget is attached and all images inside this widget are loaded. This widget show a block of html prepared in CMS (so the number of images is dynamic).
What have I tried:
override Widget.onAttach() or Widget.onLoad(). Unfortunately both of them are executed before the moment when all images are loaded.
I found gwt-image-loader library which can add a callback per image. I wan't use it due to dynamic nature of the content.
In JavaScript there is this option which works great:
$('selector').waitForImages(function() {
// do some logic
});
Maybe I missed some GWT way to do the same thing?
You can try GWT's Image.addLoadHandler()
onLoad and onAttach methods are there to inform you that the <img> tag is attached to your document and that is it. This helps in setting image attributes such as height, width, position and so on. What you are asking is, after the image is attached to document you want an handler after the image is rendered. This is not possible with the current version of GWT as per my experience. Further rendering of image depends on the network you are in, the server you are connected and so on. So instead of wanting for a render callback, try to do the work in onLoad or onAttach methods or add a loadHandler for the same
I am trying to create GTK Widget like shows in following Images
Is it possible to create it in GTK+ under C,
I tried using GtkExpander but it is not working out ...
Can any one Help....
Stripping the arrow is quite trivial. Just append the following code to you $HOME/.gtkrc-2.0 (or create it if not found):
style "pradeep" {
GtkExpander::expander-size = 0
GtkExpander::expander-spacing = 0
}
widget "*.GtkExpander" style "pradeep"
This is done by customizing the appearance using resource files. You can get the same result programmatically by changing the GtkExpander style properties.
Furthermore, you can connect your own callback to its "activate" signal and switch the background color of the widget whenever is active or not. And a lot more...
Just remember someone loves to have a consistent user interface.
If what you want is to duplicate the look, then there are two very inefficient solutions to the problem:
Write your own GTK theme engine (see Murrine or Clearlooks).
Replace your entire program by a GtkDrawingArea widget and use Cairo to draw exactly the look you want. You'll be on your own then, though, so you'll have to write all your widget placement algorithms, buttons, expanders, menus, and whatnot, from scratch.
GTK isn't really meant for this sort of thing. The whole point of GTK is that you design your user interface with the standard widgets, and they just work with whatever theme, language, or accessibility technologies your users need to use. If you design your own look and there's no way to change it, then someone with color blindness or poor eyesight won't be able to use it. Or the text will get all misaligned if someone uses your application in another language. Or at the very least, maybe someone just likes a black desktop with white lettering, and your application will stick out and look really ugly on that user's computer. If you really need to make it look exactly that way, then probably GTK isn't the right tool for you.
How to change background color of GtkTextView? I tried with normal widget set bg functionality but gtk is just changing border color of GtkText View.
Plus can some some please explain me with simple example, that how to change Text Color/Font/Text Size in GtkTextView (Whole text in GtkTextView)?
I fond some examples but they are not working..
Thnaks,
PP.
gtk_widget_override_background_color()
This the GTK 3.x+ way (until GTK 3.16). From
https://developer.gnome.org/gtk3/unstable/GtkWidget.html#gtk-widget-modify-base
"gtk_widget_modify_base has been deprecated since version 3.0 and should not be used in newly-written code. Use gtk_widget_override_background_color() instead"
UPDATE: thegtknerd notes that this method too is now deprecated and it has been since 3.16.
gtk_widget_modify_base()
http://library.gnome.org/devel/gtk/unstable/GtkWidget.html#gtk-widget-modify-base
As of gtk3, I believe the proper way to do that is through CSS. Register a gtk style sheet though GtkCssProvider, then you can write this CSS:
textview text {
background-color: #theme_bg_color;
}
We can see the relevant CSS nodes in the documentation for GtkTextView. In this case I put #theme_bg_color which is an adwaita CSS variable, but you can as well put anything that goes in a usual CSS file, like red or #ff0000.