I want to add transparent button in my application and i am using gtk. How to do it?
I am using gtk_color_button_set_alpha():
gtk_color_button_set_alpha(GtkColorButton *button, guint16 100);
But it is giving error as
error: expected expression before ‘GtkColorButton’
error: too few arguments to function ‘gtk_color_button_set_alpha’
With a fairly recent GTK+ (3.8) this should be quite easy: See opacity property and gtk_widget_set_opacity(). Note that this depends on display manager features and you cannot rely on the opacity working everywhere. You can check if it works though: gtk_widget_is_composited() should tell you that.
Related
After the PR https://github.com/codenameone/CodenameOne/pull/3233, I get the popupDialogs as I want them (on Android). They are ok, the text is correctly in the centre, margin and padding are as I want them.
But I have an issue with iOS. Sometimes, when the popup Dialog contains very few text, iOS calculates wrong Dimension for the Dialog. It happens only on iOS.
What I understood is that the implementation of Dialog popups on iOS is native, while on Android it's lightweight. Please correct me if I have misunderstood. Since the Android implementation works well, I would like to use it on iOS as well. That's the meaning of this RFE of mine:
https://github.com/codenameone/CodenameOne/issues/3234
Anyway, I change my question: even without that RFE, can I use Lightweight Popup Dialogs also on iOS?
Yes but it might be a bit tricky. If you use CSS setting the popup border becomes a huge pain because of this issue.
So you'll need to either use the designer tool and define PopupDialog to explicitly use the RoundRectBorder or you'll need to do it from code (explicitly setting this into the theme).
A hack that might work (didn't try this) is using this code in your init(Object) instead of initFirstTheme:
try {
theme = Resources.openLayered(resourceFile);
themeProps.put("PopupDialog.derive", "Dialog");
themeProps.put("PopupDialog.border", RoundRectBorder.create().
cornerRadius(2f).
shadowOpacity(60).shadowSpread(3.0f));
themeProps.put("PopupDialog.transparency", "255");
themeProps.put("PopupDialog.bgColor", background);
themeProps.put("PopupDialog.padding", "4,4,4,4");
themeProps.put("PopupDialog.padUnit", new byte[]{Style.UNIT_TYPE_DIPS, Style.UNIT_TYPE_DIPS, Style.UNIT_TYPE_DIPS, Style.UNIT_TYPE_DIPS});
UIManager.getInstance().setThemeProps(theme.getTheme(theme.getThemeResourceNames()[0]));
Resources.setGlobalResources(theme);
} catch(IOException e){
Log.e(e);
}
So I have a window, and I have coded it so that during run-time it can enter and exit full-screen mode. Entering full-screen works, but exiting places the window tile bar in reverse order.
Exit full screen code:
SetWindowLongPtr(hWnd, GWL_EXSTYLE, WS_OVERLAPPEDWINDOW);
SetWindowPos(hWnd, HWND_TOPMOST, 0, 0, 640, 480, NULL);
InvalidateRect(hWnd, NULL, TRUE);
Picture of the result: https://www.dropbox.com/s/p15eltz7b2hxx4y/window.png?dl=0
I tried using GWL_STYLE instead of GWL_EXSTYLE but that works even worse, with the window being visible but clicking anything on the window will act like the window is not there and the click on whatever is behind it...
Thanks!
Philip
Just a thought, couldn't you get the window style (with GetWindowLongPtr), store it as a member variable in you class and then use this as the style to reset in SetWindowLongPtr?
Following is uncheck code (this is assuming you are using C++),
MainWnd::OnFullScreen(...)
{
m_oldStyle = GetWindowLongPtr(GWL_EXSTYLE, m_hwd);
/*
what ever other code is necessary
*/
}
MainWnd::OnExitFullScreen(...)
{
SetWindowLongPtr(m_hwn, GWL_EXSTYLE, m_oldStyle);
/*
and other code as needed
*/
}
I've made two assumptions here:
(1) that you will have two variables, one to contain the old style (m_oldStyle) and one to hold the handle to the window (m_hwd). Note if you are doing strict SDK style coding then the handle will be passed to you as part of WndProc. If you are using MFC there should be member function in the class you derived you main window from. In other cases you are on your own.
(2) the second assumption is that SetWindowLongPtr is called prior to any change of screen type. I believe that SetWindowLongPtr is called during window construction, but it has been several years since I've done serious windows programming using Microsoft frameworks (now I tend to used QT's framework).
I have the following piece of GTK3 code:
(...)
cmd_bar = gtk_entry_new();
gtk_editable_set_editable(GTK_EDITABLE(cmd_bar), TRUE);
gtk_entry_set_visibility(GTK_ENTRY(cmd_bar), TRUE);
gtk_widget_grab_focus(GTK_WIDGET(cmd_bar));
gtk_grid_attach (GTK_GRID (grid), GTK_WIDGET(cmd_bar), 0, 1, 2, 1);
gtk_widget_show(cmd_bar);
(...)
It shows the GtkEntry correctly, however it doesn't show any input from keyboard. If I paste some string it's accepted normally.
How can I resolve this issue?
I had the same issue when I ported my application from GTK3 to GTK4, same behavior that I was able to paste and cut text in the entry but not being able to focus or freely insert text with my keyboard.
Already in my GTK3 application I had on a few widgets incorrectly set the "can-focus" property to "False" by mistake in my templates (with glade) and when porting to GTK4 they seem to have caused issues.
At first I didn't think the "can-focus" property could be the issue because my GtkEntry had it set to TRUE, the issue was that one of it's parent containers had the value set to FALSE.
Hopefully this was the issue for you as well, if it's not hopefully it's an solution for someone else.
According to the GtkWidget documentation:
[gtk_widget_grab_focus] Causes widget to have the keyboard focus for the GtkWindow it's
inside. widget must be a focusable widget, such as a GtkEntry;
something like GtkFrame won't work.
More precisely, it must have the GTK_CAN_FOCUS flag set. Use
gtk_widget_set_can_focus() to modify that flag.
The widget also needs to be realized and mapped. This is indicated by
the related signals. Grabbing the focus immediately after creating the
widget will likely fail and cause critical warnings.
For an explanation of realize and map, check "Those “realize” & “map” widget signals".
The Gtk+ 3 migration guide shows how the GdkEventExpose.region field can be used to provide a fine-grained area for re-rendering widgets. We already do something like this in Inkscape to avoid rendering excessive amounts of complicated stuff on our drawing canvas.
However, the example in the guide shows how to do this for the old Gtk+ 2 expose_event handler.
How do I do the equivalent in a new Gtk+ 3 draw handler, which receives a "ready-clipped" Cairo context as a parameter, rather than a GdkEventExpose?
I guess one possibility is to use cairo_copy_clip_rectangle_list on the "ready-clipped" cairo context to obtain a list of rectangles that make up the region to draw. Does anyone have any experience of using this? Does it seem like a sensible approach?
Yes, you should use cairo_copy_clip_rectangle_list() on the cairo_t that you get in your widget's ::draw() signal handler. See this commit for an example:
http://git.gnome.org/browse/vte/commit/?id=21a064ac8b5925108b0ab9bd6516664c8cd3e268
Since I have not much clue, I decided to check the source code. GDK emits a GDK_EXPOSE event on a window and creates the GdkEventExpose instance for this.
This event is then handled in gtk/gtkmain.c via gtk_widget_send_expose():
http://git.gnome.org/browse/gtk+/tree/gtk/gtkwidget.c?id=eecb9607a5c0ee38eadb446545beccd0922cb0b8#n6104
This function clips the cairo_t to GdkEventExpose.region, as you already learned in the docs.
This then calls _gtk_widget_draw_internal() which emits the actual draw signal:
http://git.gnome.org/browse/gtk+/tree/gtk/gtkwidget.c?id=eecb9607a5c0ee38eadb446545beccd0922cb0b8#n5726
As far as I can see, nothing here let's you access the clip region directly. In gtk_widget_send_expose() the GdkEvent is added as userdata to the cairo context. However, this is not accessible, because all the involved functions and variables are static. So you'll have to use cairo_copy_clip_rectangle_list().
However, this sounds quite inefficent. First gdk_cairo_region transforms the region into a number of calls to cairo_rectangle and then cairo transforms this from its internal representation into a cairo_rectangle_list_t (which may fail if the clip is, for some reason, not a region). If you see this being slow, it might make sense to have some shortcut for this added to gtk directly.
Ive been googling this alot but can't find any working solution. Im using Shell Integration Library to cerate custom Window Chrome and I also need drop shadows for this window. Some say setting GlassFrameThickness to -1 do the trick but its not working for me. And Jeremiah Morrill suggested using DwmExtendFrameIntoClientArea. Ive tried that and it works, sort of. The shadows looks ok but when the window is shown it is first shown as a glass-frame and then a second later the real content is superimposed. This causes to much flickering for me. Is there any way to get rid of this flickering or is there any better way using only Shell Integration Library?
I had a similar problem where it wouldn't display any shadow when using a custom chrome. It worked fine when using the glass.
I got a shadow by setting GlassFrameThickness="0,0,0,1". The glass didn't show and I got the shadow.
Be warned, the shadow is a simple RECT to Windows, so if you have a funky chrome with transparencies it may look funny.
Also if you support the maximized state be aware the you'll need to set a margin on your top-level panel element of "8,8,8,8" when in maximized mode. All other modes should be "0,0,0,0".
To alimbada, the WindowStyle defaults to None on custom chrome.
The Shell Integration Library uses DwmExtendFrameIntoClientArea, plus handling of several Window messages to get the effects. If you're using the full window rect (i.e. no rounded corners) then setting it to (0,0,0,1) as suggested will give you the drop shadows as you want. If you want to simulate the rounded corners of Aero, then setting it to (8,8,8,8) will extend the glass frame enough that the corners also stay rounded, and then you're responsible for not drawing over the corners of the rectangle. The shape of the drop shadow doesn't change regardless of the glass frame thickness.
The flashing you're seeing when setting the thickness to -1 still exists even when not fully extending the glass frame. What's happening is the window is getting shown while the content is still compositing. What you can do is simplify the default UI so it displays quicker (or you can stage it, bringing in a simnple background first and then replacing it with something usable), or you can create and show the window off-screen, and then move it to the desired start location once the content has been rendered. The easy way to detect when it's probably ready is to invoke a DispatchTimer with Priority=Loaded. That should only get invoked once the basic first layout has been completed.