I want a button's callback method to instantiate a window (with editor) each time the button is clicked, possibly resulting in multiple windows with editors visible simultaneously. For now I would be happy if just one would appear -- it doesn't.
Comments regarding FLTK and C++ programming practice in general are also welcome.
#include <FL/Fl.H>
#include <FL/Fl_Window.H>
#include <FL/Fl_Button.H>
#include <FL/Fl_Text_Editor.H>
#include <FL/Fl_Text_Buffer.H>
class MainWin : public Fl_Window {
public:
MainWin(int w, int h, const char *title);
~MainWin();
Fl_Button* gobtn;
Fl_Text_Editor* ed; // first editor included with main window
Fl_Text_Buffer* buf;
private:
static void gomthd(Fl_Widget *, void *); // "go" method
};
class AdditionalWin : public Fl_Window { // more editors if necessary
public:
AdditionalWin(int w, int h, const char *title);
~AdditionalWin();
Fl_Text_Editor *ed;
Fl_Text_Buffer *buf;
};
int main () {
MainWin win(105, 405, "main");
return Fl::run();
}
MainWin::MainWin(int w, int h, const char* title):Fl_Window(w,h,title) {
gobtn = new Fl_Button(8, 38, 35, 20, "go");
gobtn->callback(gomthd, this);
ed = new Fl_Text_Editor(6, 67, 93, 331);
buf = new Fl_Text_Buffer();
ed->buffer(buf);
end();
resizable(this);
show();
}
AdditionalWin::AdditionalWin(int w, int h, const char *title):Fl_Window(w, h, title) {
ed = new Fl_Text_Editor(6, 67, 93, 331);
buf = new Fl_Text_Buffer();
ed->buffer(buf);
end();
resizable(this);
show();
}
void MainWin::gomthd(Fl_Widget* o, void* v) {
AdditionalWin awin(105, 405, "more");
awin.position(1, 1);
awin.show(); // ??? nothing appears
}
MainWin::~MainWin(){}
AdditionalWin::~AdditionalWin(){}
Very late to the party but still: I think the new window never shows, because awin, being a local variable, gets destroyed as soon as the MainWin::gomthd() function returns.
I am using C++ Builder 10.2.2 Tokyo with FireMonkey (FMX).
I want to add drag and drop functionality to a TTreeView, so a user can rearrange the order of the tree items. I have added a handler to the TTreeView.OnMouseDown event, based on this Drag and Drop sample project.
With this, the program can now drag and drop to rearrange items, but it seems that there is some default behavior to move a TTreeViewItem to be a child of the TTreeViewItem it is dropped onto, instead of inserting after that item.
How can I override this default behavior, so that a TTreeViewItem is inserted at the same level in the TTreeView, and at an index 1 greater than the TTreeViewItem it is dropped onto?
Following on Abdullah's suggestion, you can achieve this by creating a custom component. Directions to create a custome component in general are here. I recommend installing it in Standard on the Tool Palette, as that's where TTreeView is.
The custom component, here called TMyTreeView, has this in the header in particular:
class PACKAGE TMyTreeView : public TTreeView
{
private:
bool IsAncestor (TTreeViewItem* oItem, TTreeViewItem* oTargetItem);
protected:
int DragDelta;
void StartDrag ();
void __fastcall DragDrop (const Fmx::Types::TDragObject &Data, const System::Types::TPointF &Point);
void __fastcall MouseDown (System::Uitypes::TMouseButton Button, System::Classes::TShiftState Shift, float X, float Y);
void __fastcall MouseMove (System::Classes::TShiftState Shift, float X, float Y);
public:
__fastcall TMyTreeView(TComponent* Owner);
__fastcall ~TMyTreeView ();
TBitmap* DragBmp;
TPointF MouseDownPoint;
TTreeViewItem* DragStartItem;
__published:
};
//---------------------------------------------------------------------------
where the functions are as follows in the corresponding cpp file:
__fastcall TMyTreeView::TMyTreeView(TComponent* Owner)
: TTreeView(Owner)
{
DragBmp = NULL;
DragStartItem = NULL;
DragDelta = 5;
}
//---------------------------------------------------------------------------
__fastcall TMyTreeView::~TMyTreeView ()
{
if (DragBmp)
delete DragBmp;
}
//---------------------------------------------------------------------------
void __fastcall TMyTreeView::MouseMove (System::Classes::TShiftState Shift, float X, float Y)
{
TTreeView::MouseMove (Shift, X, Y);
if ((abs (X-MouseDownPoint.X) > DragDelta) || (abs (Y-MouseDownPoint.Y) > DragDelta))
StartDrag ();
}
//---------------------------------------------------------------------------
void TMyTreeView::StartDrag ()
{
if (!AllowDrag)
return;
if (!DragStartItem)
return;
if (DragBmp)
delete DragBmp;
_di_IFMXDragDropService service;
if ((TPlatformServices::Current->SupportsPlatformService (__uuidof(IFMXDragDropService)) &&
(service = TPlatformServices::Current->GetPlatformService (__uuidof(IFMXDragDropService)))))
{
TDragObject dragData;
if (!DragStartItem)
return;
dragData.Source = DragStartItem;
DragBmp = DragStartItem->MakeScreenshot ();
dragData.Data = DragBmp;
service->BeginDragDrop ((TForm*)this->Owner, dragData, DragBmp);
DragStartItem = NULL;
}
}
//---------------------------------------------------------------------------
void __fastcall TMyTreeView::MouseDown (System::Uitypes::TMouseButton Button, System::Classes::TShiftState Shift, float X, float Y)
{
TTreeView::MouseDown (Button, Shift, X, Y);
if (AllowDrag)
{
DragStartItem = ItemByPoint (X, Y);
MouseDownPoint.X = X;
MouseDownPoint.Y = Y;
}
else
DragStartItem = NULL;
}
//---------------------------------------------------------------------------
void __fastcall TMyTreeView::DragDrop (const Fmx::Types::TDragObject &Data, const System::Types::TPointF &Point)
{
TTreeViewItem* item = ItemByPoint (Point.X, Point.Y);
if (!item)
return;
TTreeViewItem* srcItem = (TTreeViewItem*)Data.Source;
if (!srcItem)
return;
if (IsAncestor (srcItem, item))
return;
if (item->ParentItem ())
item->ParentItem ()->InsertObject (item->Index, srcItem);
else
this->InsertObject (item->Index, srcItem);
//TTreeView::DragDrop (Data, Point);
}
//---------------------------------------------------------------------------
bool TMyTreeView::IsAncestor (TTreeViewItem* oItem, TTreeViewItem* oTargetItem)
{
for (int i=0; i<oItem->Count; i++)
{
TTreeViewItem* item = oItem->Items [i];
if (item == oTargetItem)
return true;
if (IsAncestor (item, oTargetItem))
return true;
}
return false;
}
//---------------------------------------------------------------------------
After installing the custom component to your Tool Palette, you can then add it to your form as you would any other component.
Special thanks to Mike Sutton, who had code to modify an earlier version of TTreeView here.
Once added to a form, set the TMyTreeView control's AllowDrag to true.
According to https://developer.gnome.org/gdk3/stable/GdkScreen.html#gdk-screen-get-active-window,
gdk_screen_get_active_window has been deprecated since version 3.22 and should not be used in newly-written code.
But, what should be used instead? (This is one of many deprecated GdkScreen functions.)
To be specific, how would I obtain the location and geometry of the active window?
Edit 12/10/16: After a couple of days looking into this, I've come to the conclusion the answer to this question is outside developer.gnome.org. It may be that separate code needs to be written directly targeting X11, wayland, and mir.
For what it's worth, below is get_window-areas.c that I have written exploring what can be found in Gtk without using deprecated functions. It seems there isn't a way to get window titles or active status; so that, I could not duplicate the functionality of #theGtknerd's answer which uses unstable Wnck libraries.
I am just learning Gtk, so I do appreciate any comments for improving this. I started with the empty window code https://developer.gnome.org/gtk3/stable/gtk-getting-started.html#id-1.2.3.5, added a textview with buffer to it, and then inserted information about the geometry and location of each window into the text buffer.
gcc `pkg-config --cflags gtk+-3.0` -o get_window-areas get_window-areas.c `pkg-config --libs gtk+-3.0`
Compile get_window-areas.c below with the gcc command above.
#include <gtk/gtk.h>
static void
activate (GtkApplication* app,
gpointer user_data)
{
GtkWidget *window = NULL;
GtkWidget *text_view;
GtkTextBuffer *buffer;
int x = 0, y = 0, width = 0, height = 0;
char char_x[5], char_y[5], char_width[5], char_height[5];
GdkScreen *screen;
GdkWindow *dwindow;
GList *gl_item = NULL, *gl = NULL;
window = gtk_application_window_new (app);
screen = gtk_window_get_screen (GTK_WINDOW(window));
buffer = gtk_text_buffer_new (NULL);
text_view = gtk_text_view_new_with_buffer (buffer);
gtk_container_add (GTK_CONTAINER (window), text_view);
if(screen != NULL)
{
gl = gdk_screen_get_window_stack(screen);
for (gl_item = g_list_first(gl); gl_item != NULL; gl_item = gl_item->next)
{
dwindow=gl_item->data;
gdk_window_get_root_origin(dwindow, &x, &y);
width = gdk_window_get_width(dwindow);
height = gdk_window_get_height(dwindow);
g_object_unref(dwindow);
snprintf (char_x, 5, "%d", x);
snprintf (char_y, 5, "%d", y);
snprintf (char_width, 5, "%d", width);
snprintf (char_height, 5, "%d", height);
gtk_text_buffer_insert_at_cursor(buffer,char_width,-1);
gtk_text_buffer_insert_at_cursor(buffer,"x", -1);
gtk_text_buffer_insert_at_cursor(buffer,char_height,-1);
gtk_text_buffer_insert_at_cursor(buffer," at (", -1);
gtk_text_buffer_insert_at_cursor(buffer,char_x, -1);
gtk_text_buffer_insert_at_cursor(buffer,",", -1);
gtk_text_buffer_insert_at_cursor(buffer,char_y,-1);
gtk_text_buffer_insert_at_cursor(buffer,")\n", -1);
};
g_list_free (gl);
}
else {gtk_text_buffer_insert_at_cursor(buffer, "Failed to get default screen.\n", -1);}
gtk_widget_show_all (window);
}
int
main (int argc,
char **argv)
{
GtkApplication *app;
int status;
app = gtk_application_new ("com.github.colinkeenan.silentcast", G_APPLICATION_FLAGS_NONE);
g_signal_connect (app, "activate", G_CALLBACK (activate), NULL);
status = g_application_run (G_APPLICATION (app), argc, argv);
g_object_unref (app);
return status;
}
Here is Python code that gets the active window and prints its geometry.
#!/usr/bin/python
import gi
gi.require_version('Wnck', '3.0')
from gi.repository import Wnck
screen = Wnck.Screen.get_default()
screen.force_update() # recommended per Wnck documentation
# loop all windows
for window in screen.get_windows():
if window.is_active() == True:
print (window.get_geometry())
window_name = window.get_name()
print (window_name)
# clean up Wnck (saves resources, check documentation)
window = None
screen = None
Wnck.shutdown()
The documentation is https://developer.gnome.org/libwnck/stable/WnckWindow.html.
Edit: I am trying to compile the C I have with:
gcc `pkg-config --cflags --libs libwnck-3.0` -o wnck wnck.c
and I get the error:
/usr/include/libwnck-3.0/libwnck/window.h:30:2: error: #error "libwnck should only be used if you understand that it's subject to frequent change, and is not supported as a fixed API/ABI or as part of the platform"
there is a workaround, but I am not sure Wnck is a good replacement for GdkScreen. I really do not know what to tell you at this point.
(edit 3/11/17 to eliminate memory leaks by closing display whenever opened)
(edit 3/6/17 to initialize s in get_top_window)
(edit 12/24 to provide a complete answer for X11, and marking as correct answer until somebody has a general solution). It is part of my in progress rewriting/refactoring of my silentcast application (previously just a series of bash scripts using yad for the UI) on github, although I have not yet put any of this Gtk code on github.
My "Correct Answer" below allows you to actually get the active GdkWindow, it's geometry & extents, or the active X11 window with children, and it's geometry.
Correct Answer
(note that it only applies to X11 so should include and compile against gtk/gtkx.h, not gtk/gtk.h)
.h file
/*
* Filename: SC_X11_get_active_window.h
* App Name: Silentcast <https://github.com/colinkeenan/silentcast>
* Copyright © 2016, 2017 Colin N Keenan <colinnkeenan#gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Library General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* Description: defines some custom X11 error messags and exposes 3 functions:
* SC_get_active_gdkwindow (...), SC_get_geomeotry_for (...),
* and SC_get_active_windows_and_geometry (...)
*/
#include <gtk/gtkx.h>
#define SC_X11_ERROR0 " \n"
#define SC_X11_ERROR1 "Failed to connect to X server.\n"
#define SC_X11_ERROR2 "x11 error trying to get focused window\n"
#define SC_X11_ERROR3 "X11 reports no focused window\n"
#define SC_X11_ERROR4 "X11 error trying to get top window\n"
#define D_ERR 1
#define FOCUS_ERR1 2
#define FOCUS_ERR2 3
#define TOP_ERR 4
#define UKN_ERR 5
#define SC_X11_E1 D_ERR
#define SC_X11_E2 FOCUS_ERR1
#define SC_X11_E3 FOCUS_ERR2
#define SC_X11_E4 TOP_ERR
#define SC_X11_E0 UKN_ERR
unsigned int SC_get_active_X11window (Window *w, Window* *w_children, ssize_t *n);
gboolean SC_get_active_gdkwindow (Window aw, Window *aw_children, ssize_t n, GdkWindow* *gdkwindow);
void SC_get_geometry_for (Window aw, Window *aw_children, ssize_t n, int *x, int *y,
unsigned int *width, unsigned int *height, GdkRectangle *extents, GdkWindow* *gdkwindow);
gboolean SC_get_active_windows_and_geometry (Window *aw, Window* *aw_children, ssize_t *n,
int *x, int *y, unsigned int *width, unsigned int *height, GdkRectangle *extents, GdkWindow* *gdkwindow);
.c file
/*
* Filename: SC_X11_get_active_window.c
* App Name: Silentcast <https://github.com/colinkeenan/silentcast>
* Copyright © 2016 Colin N Keenan <colinnkeenan#gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Library General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* Description: adapted from "get the active window on X window system"
* https://gist.github.com/kui/2622504
* to get Gdk geometry of the active window, both the
* inner window and the extents
*/
#include "SC_X11_get_active_window.h"
Bool xerror = False;
static int handle_error (Display* display, XErrorEvent* error) {
xerror = True;
return 1;
}
static int get_focus_window (Display* d, Window *w) {
int revert_to;
XGetInputFocus (d, w, &revert_to);
if (xerror) return FOCUS_ERR1; //X error trying to get focused window
else if (w == None) return FOCUS_ERR2; //no focused window
else return 0;
}
static int get_top_window (Display* d, Window start, Window *w, Window* *w_children, ssize_t *n) {
Window parent = start, root = None, *children = NULL;
*w = start;
unsigned int nchildren;
Status s = XQueryTree (d, *w, &root, &parent, &children, &nchildren), s_prev;
/* ultimately trying to get *w and *w_children */
while (parent != root && !xerror) {
*w = parent; //previous parent
s_prev = s; //previous status of XQueryTree
if (s_prev) {
*w_children = children; //previous children
*n = nchildren; //previous number of children
}
s = XQueryTree (d, *w, &root, &parent, &children, &nchildren);
/* When parent == root, the previous "parent" is the top window.
* Save the children of the top window too, but XFree all other
* children.
*/
if (parent != root) {
// parent is not root, so previous parent wasn't top window, so don't need it's children
if (s_prev) XFree (*w_children);
} else
if (s) XFree (children); // don't keep the children of root either
}
if (xerror) return TOP_ERR;
else return 0;
}
unsigned int
SC_get_active_X11window (Window *w, Window* *w_children, ssize_t *n)
{
Display* d = NULL;
unsigned int e = 0;
XSetErrorHandler (handle_error);
d = XOpenDisplay (NULL);
if (d == NULL) {
return D_ERR;
} else {
/* set w to the focused window */
e = get_focus_window (d, w);
if (e) { //if error
XCloseDisplay (d);
return e;
}
/* get_top_window will set w to the top focused window (active window) */
e = get_top_window (d, *w, w, w_children, n);
if (e) { //if error
XCloseDisplay (d);
return e;
}
XCloseDisplay(d);
}
return 0; //no error
}
/* SC_get_active_gdkwindow (...) tries to match a GdkWindow to one of the passed X11
* windows (supposed to be the active X11 window and it's n children), and returns
* TRUE if such a match is found, FALSE if not
*/
gboolean
SC_get_active_gdkwindow (Window aw, Window *aw_children, ssize_t n, GdkWindow* *gdkwindow) {
ssize_t i = 0;
GdkWindow *dwindow = NULL;
GdkScreen *screen = NULL;
GList *gl_item = NULL, *gl = NULL;
gboolean active_window_found = FALSE;
screen = gdk_screen_get_default ();
if (screen != NULL) {
/* Go through all windows known to Gtk and check XID against active X11 window, aw. */
gl = gdk_screen_get_window_stack (screen);
for (gl_item = g_list_first (gl); !active_window_found && gl_item != NULL; gl_item = gl_item->next) {
dwindow = gl_item->data;
if (gdk_x11_window_get_xid (dwindow) == aw) active_window_found = TRUE;
else for (i = 0; i < n; i++) //aw didn't match this dwindow, so check all of aw_children
if (gdk_x11_window_get_xid (dwindow) == aw_children[i]) active_window_found = TRUE;
if (!active_window_found) g_object_unref (dwindow);
else *gdkwindow = dwindow;
}
g_list_free (gl);
}
return active_window_found;
}
/* SC_get_geometry_for (...) trys to get the Gdk geometry for the GdkWindow
* matching the passed X11 window with children, getting both the internal
* window geometry and it's extents (title-bar/frame). If can't get Gdk info
* will get the X11 geometry, setting both inner and extents geometry to
* the same values.
*/
void
SC_get_geometry_for (Window aw, Window *aw_children, ssize_t n, GdkRectangle *win_rect, GdkRectangle *extents, GdkWindow* *dwindow) {
unsigned int bwidth = 0, depth = 0, width, height;
int x, y;
Window root = 0;
if (SC_get_active_gdkwindow (aw, aw_children, n, dwindow)) {
gdk_window_get_frame_extents (*dwindow, extents); //{top-left corner, width & height} of title-bar/borders
gdk_window_get_origin(*dwindow, &x, &y); //top-left corner of interior window (not title bar/borders)
width = gdk_window_get_width (*dwindow); //width of interior window
height = gdk_window_get_height (*dwindow); //height of interior window
win_rect->x = x;
win_rect->y = y;
win_rect->width = (int) width;
win_rect->height = (int) height;
} else {
fprintf (stderr, "Failed to get GdkWindow. Falling back on X11 geometry of active window, saved as both extents and interior geometry.");
Display* d = XOpenDisplay (NULL);
if (d) {
XGetGeometry (d, aw, &root, &x, &y, &width, &height, &bwidth, &depth);
XCloseDisplay (d);
extents->x = x;
extents->y = y;
extents->width = (int) width;
extents->height = (int) height;
}
}
}
/* SC_get_active_windows_and_geometry (...) calls get_active_x11window (...) to get the active X11 window
* and it's children, then calls SC_get_geometry_for (...) to get geometry (hopefully Gdk) that matches
*/
gboolean
SC_get_active_windows_and_geometry (Window *aw, Window* *aw_children, ssize_t *n,
GdkRectangle *win_rect, GdkRectangle *extents, GdkWindow* *dwindow) {
switch (SC_get_active_X11window(aw, aw_children, n)) { get aw, aw_children, and n (number of children)
case 0: SC_get_geometry_for (*aw, *aw_children, *n, win_rect, extents, dwindow); return TRUE;
case SC_X11_E1: fprintf (stderr, SC_X11_ERROR1); break;
case SC_X11_E2: fprintf (stderr, SC_X11_ERROR2); break;
case SC_X11_E3: fprintf (stderr, SC_X11_ERROR3); break;
case SC_X11_E4: fprintf (stderr, SC_X11_ERROR4); break;
}
return FALSE; //failed to get active window due to X11 error
}
My Previous answer that usually got correct geometry, but not the window
I have adapted code from "get the active window on X window system" https://gist.github.com/kui/2622504 to work with my example in the question. I turned it into a library. I'm not marking this as the correct answer because this is the first library file I've ever written and I'm completely new to Gtk as well. I also don't have much experience writing C code. Finally, the correct answer should include libraries for X11, Wayland, and MIR. I would be happy to see an answer including my library with improvements + the missing two libraries.
Compile below with:
gcc `pkg-config --cflags gtk+-3.0` -o get_window-areas X11_get_active_window_geometry.c get_window-areas.c `pkg-config --libs gtk+-3.0` -lX11
X11_get_active_window_geometry.h
#include <X11/Xlib.h>
#define SC_X11_ERROR0 "Uknown error from get_actve_window_geometry.\n"
#define SC_X11_ERROR1 "Failed to connect to X server.\n"
#define SC_X11_ERROR2 "x11 error trying to get focused window\n"
#define SC_X11_ERROR3 "X11 reports no focused window\n"
#define SC_X11_ERROR4 "X11 error trying to get top window\n"
#define SC_X11_ERROR5 "X11 error trying to get the active-window geometry.\n"
#define D_ERR 1
#define FOCUS_ERR1 2
#define FOCUS_ERR2 3
#define TOP_ERR 4
#define GEOM_ERR 5
#define SC_X11_E1 D_ERR
#define SC_X11_E2 FOCUS_ERR1
#define SC_X11_E3 FOCUS_ERR2
#define SC_X11_E4 TOP_ERR
#define SC_X11_E5 GEOM_ERR
unsigned int get_active_window_geometry (int *x, int *y, unsigned int *width, unsigned int *height);
X11_get_active_window_geometry.c
#include "X11_get_active_window_geometry.h"
Bool xerror = False;
static int handle_error (Display* display, XErrorEvent* error) {
xerror = True;
return 1;
}
static int get_focus_window (Display* d, Window *w) {
int revert_to;
XGetInputFocus (d, w, &revert_to);
if (xerror) return FOCUS_ERR1; //X error trying to get focused window
else if (w == None) return FOCUS_ERR2; //no focused window
else return 0;
}
static int get_top_window (Display* d, Window start, Window *w){
Window parent = start, root = None, *children;
*w = start;
unsigned int nchildren;
Status s;
while (parent != root && !xerror) {
*w = parent;
s = XQueryTree (d, *w, &root, &parent, &children, &nchildren);
if (s)
XFree (children);
}
if (xerror) return TOP_ERR;
else return 0;
}
unsigned int get_active_window_geometry (int *x, int *y,
unsigned int *width, unsigned int *height)
{
Display* d = NULL;
Window root, w;
unsigned int bwidth = 0, depth = 0, e = 0;
XSetErrorHandler (handle_error);
d = XOpenDisplay (NULL);
if (d == NULL) {
return D_ERR;
} else {
e = get_focus_window (d,&w); //get focused window w
if (e) return e;
e = get_top_window (d, w, &w); //get top focused window w (the active window)
if (e) return e;
XGetGeometry (d, w, &root, x, y, width, height, &bwidth, &depth);
if (xerror) return GEOM_ERR;
}
return 0;
}
get_active_window.c
#include <gtk/gtk.h>
#include "X11_get_active_window_geometry.h"
static void
activate (GtkApplication* app,
gpointer user_data)
{
GtkWidget *window = NULL, *text_view;
GtkTextBuffer *buffer;
unsigned int width = 0, height = 0, widtha = 0, heighta = 0, iwidtha = 0, iheighta = 0;
int x = 0, y = 0, xa = 0, ya = 0, ixa =0, iya = 0;
GdkRectangle extents= { 0, 0, 0, 0 };
char char_x[5], char_y[5], char_width[5], char_height[5];
GdkScreen *screen;
GdkWindow *dwindow;
GList *gl_item = NULL, *gl = NULL;
window = gtk_application_window_new (app);
screen = gtk_window_get_screen (GTK_WINDOW(window));
buffer = gtk_text_buffer_new (NULL);
text_view = gtk_text_view_new_with_buffer (buffer);
gtk_container_add (GTK_CONTAINER (window), text_view);
#define ADD_TEXT(STRING) gtk_text_buffer_insert_at_cursor (buffer,STRING,-1)
#define ADD_INT(CHAR_INT,INT) snprintf (CHAR_INT, 5, "%d", INT); ADD_TEXT(CHAR_INT);
#define ADD_GEOMETRY_TEXT(X,Y,WIDTH,HEIGHT) ADD_INT(char_width, WIDTH); ADD_TEXT("x"); ADD_INT(char_height, HEIGHT); ADD_TEXT(" at ("); ADD_INT(char_x, X); ADD_TEXT(","); ADD_INT(char_y, Y); ADD_TEXT(")\n");
/* get active window geometry using X11 and handle error, if any*/
switch (get_active_window_geometry(&xa, &ya, &widtha, &heighta)) {
case 0:
ADD_TEXT("GEOMETRY FOR ACTIVE WINDOW USING X11\n");
ADD_GEOMETRY_TEXT(xa, ya, widtha, heighta);
ADD_TEXT("\n");
break;
case SC_X11_E1:
ADD_TEXT(SC_X11_ERROR1);
break;
case SC_X11_E2:
ADD_TEXT(SC_X11_ERROR2);
break;
case SC_X11_E3:
ADD_TEXT(SC_X11_ERROR3);
break;
case SC_X11_E4:
ADD_TEXT(SC_X11_ERROR4);
break;
case SC_X11_E5:
ADD_TEXT(SC_X11_ERROR5);
break;
default:
ADD_TEXT(SC_X11_ERROR0);
}
/* get window geometry for all windows using Gtk and identify the active one by comparison with X11 result*/
if (screen != NULL) {
ADD_TEXT("GEOMETRY FOR ALL WINDOWS USING Gtk:\n\n");
gl = gdk_screen_get_window_stack (screen);
for (gl_item = g_list_first (gl); gl_item != NULL; gl_item = gl_item->next) {
dwindow=gl_item->data;
gdk_window_get_frame_extents (dwindow, &extents); //{top-left corner, width & height} of title-bar/borders
ADD_TEXT("Entirety of Window: ");
ADD_GEOMETRY_TEXT(extents.x, extents.y, extents.width, extents.height);
gdk_window_get_origin(dwindow, &x, &y); //top-left corner of interior window (not title bar/borders)
width = gdk_window_get_width (dwindow); //width of interior window
height = gdk_window_get_height (dwindow); //height of interior window
ADD_TEXT("Interior of Window: ");
ADD_GEOMETRY_TEXT(x, y, width, height);
ADD_TEXT("\n");
/*If extents matches active window geometry, save interior window geometry */
if (extents.x == xa && extents.y == ya && extents.width == widtha && extents.height == heighta) {
ixa = x; iya = y; iwidtha = width; iheighta = height;
}
g_object_unref (dwindow);
};
g_list_free (gl);
ADD_TEXT("MATCHING THE ACTIVE WINDOW REPORTED BY X11 WITH THE GTK WINDOW GEOMETRIES:\n");
ADD_TEXT("Entirety of Active Window: ");
ADD_GEOMETRY_TEXT(xa, ya, widtha, heighta);
ADD_TEXT("Interior of Active Window: ");
ADD_GEOMETRY_TEXT(ixa, iya, iwidtha, iheighta);
} else {
ADD_TEXT("Failed to get default screen.\n");
}
gtk_widget_show_all (window);
}
int
main (int argc,
char **argv)
{
GtkApplication *app;
int status;
app = gtk_application_new ("com.github.colinkeenan.silentcast", G_APPLICATION_FLAGS_NONE);
g_signal_connect (app, "activate", G_CALLBACK (activate), NULL);
status = g_application_run (G_APPLICATION (app), argc, argv);
g_object_unref (app);
return status;
}
I would like to make the background transparent, and only the widgets are visible.
Here is my code:
#include <gtk/gtk.h>
int main (int argc, char *argv[])
{
gtk_init (&argc, &argv);
GtkWidget *window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
// Title
gtk_window_set_title(GTK_WINDOW (window), "Transparency");
//gtk_window_set_opacity(GTK_WINDOW(window), 0.5);
// CSS
GtkCssProvider *provider = gtk_css_provider_new();
GdkDisplay *display = gdk_display_get_default();
GdkScreen *screen = gdk_display_get_default_screen(display);
gtk_style_context_add_provider_for_screen(screen, GTK_STYLE_PROVIDER (provider), GTK_STYLE_PROVIDER_PRIORITY_USER);
gtk_css_provider_load_from_data(GTK_CSS_PROVIDER (provider),
"GtkWindow {\n"
" background-color: rgba(0,0,0,0);\n"
"}\n",
-1, NULL);
g_object_unref (provider);
// Window
gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER);
gtk_window_resize(GTK_WINDOW(window), 400, 300);
gtk_widget_show_all(window);
gtk_main();
return 0;
}
I use gtk3. When the program execute, it just shows black. The CSS (or rgba) function does not work.
I try to use gtk_window_set_opacity(), but it also just shows black.
How do I fix my code?
I followed the link suggested by the comment, but unfortunately it was written for Gtk 2. I have re-worked it for Gtk 3. (I am using Gtk 3.8, but as far as I know it does not use anything deprecated in Gtk 3.10). The program produces a green semi-transparent square with button in it. Of course, you could make the square completely transparent by changing the last argument for the function cairo_set_source_rgba to 0.
Note: I compiled this with the following command (assuming you call the file transparent.c):
gcc -o transparent transparent.c `pkg-config gtk+-3.0 --libs --cflags`
Here is the code:
Version for C
/**
* Original code by: Mike - http://plan99.net/~mike/blog (now a dead link--unable to find it).
* Modified by karlphillip for StackExchange:
* (https://stackoverflow.com/questions/3908565/how-to-make-gtk-window-background-transparent)
* Re-worked for Gtk 3 by Louis Melahn, L.C., January 30, 2014.
*/
#include <gtk/gtk.h>
static void screen_changed(GtkWidget *widget, GdkScreen *old_screen, gpointer user_data);
static gboolean draw(GtkWidget *widget, cairo_t *new_cr, gpointer user_data);
static void clicked(GtkWindow *win, GdkEventButton *event, gpointer user_data);
int main(int argc, char **argv)
{
gtk_init(&argc, &argv);
GtkWidget *window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER);
gtk_window_set_default_size(GTK_WINDOW(window), 400, 400);
gtk_window_set_title(GTK_WINDOW(window), "Alpha Demo");
g_signal_connect(G_OBJECT(window), "delete-event", gtk_main_quit, NULL);
gtk_widget_set_app_paintable(window, TRUE);
g_signal_connect(G_OBJECT(window), "draw", G_CALLBACK(draw), NULL);
g_signal_connect(G_OBJECT(window), "screen-changed", G_CALLBACK(screen_changed), NULL);
gtk_window_set_decorated(GTK_WINDOW(window), FALSE);
gtk_widget_add_events(window, GDK_BUTTON_PRESS_MASK);
g_signal_connect(G_OBJECT(window), "button-press-event", G_CALLBACK(clicked), NULL);
GtkWidget* fixed_container = gtk_fixed_new();
gtk_container_add(GTK_CONTAINER(window), fixed_container);
GtkWidget* button = gtk_button_new_with_label("button1");
gtk_widget_set_size_request(button, 100, 100);
gtk_container_add(GTK_CONTAINER(fixed_container), button);
screen_changed(window, NULL, NULL);
gtk_widget_show_all(window);
gtk_main();
return 0;
}
gboolean supports_alpha = FALSE;
static void screen_changed(GtkWidget *widget, GdkScreen *old_screen, gpointer userdata)
{
/* To check if the display supports alpha channels, get the visual */
GdkScreen *screen = gtk_widget_get_screen(widget);
GdkVisual *visual = gdk_screen_get_rgba_visual(screen);
if (!visual)
{
printf("Your screen does not support alpha channels!\n");
visual = gdk_screen_get_system_visual(screen);
supports_alpha = FALSE;
}
else
{
printf("Your screen supports alpha channels!\n");
supports_alpha = TRUE;
}
gtk_widget_set_visual(widget, visual);
}
static gboolean draw(GtkWidget *widget, cairo_t *cr, gpointer userdata)
{
cairo_save (cr);
if (supports_alpha)
{
cairo_set_source_rgba (cr, 0.5, 1.0, 0.50, 0.5); /* transparent */
}
else
{
cairo_set_source_rgb (cr, 1.0, 1.0, 1.0); /* opaque white */
}
/* draw the background */
cairo_set_operator (cr, CAIRO_OPERATOR_SOURCE);
cairo_paint (cr);
cairo_restore (cr);
return FALSE;
}
static void clicked(GtkWindow *win, GdkEventButton *event, gpointer user_data)
{
/* toggle window manager frames */
gtk_window_set_decorated(win, !gtk_window_get_decorated(win));
}
Version for C++
I include a very similar program, this time written for gtkmm in C++. It can be compiled with the following command:
g++ -otransparent main.cpp transparent.cpp `pkg-config gtkmm-3.0 --cflags --libs` -std=c++11
Note that I used some of the features in the new C++-11 standard, so you will need a compiler that supports them. (If you don't have one, you just have to replace the auto keyword when it appears with the appropriate type, which you can figure out from the definition of the function.) There are three files: main.cpp, transparent.h, and transparent.cpp.
main.cpp
/**
* main.cpp
*
* Code adapted from 'alphademo.c' by Mike
* (http://plan99.net/~mike/blog--now a dead link--unable to find it.)
* as modified by karlphillip for StackExchange:
* (https://stackoverflow.com/questions/3908565/how-to-make-gtk-window-background-transparent)
* Re-worked for Gtkmm 3.0 by Louis Melahn, L.C. January 31, 2014.
*/
#include "transparent.h"
#include
int main (int argc, char *argv[])
{
Glib::RefPtr app = Gtk::Application::create(argc, argv, "org.gtkmm.example.transparent");
Transparent transparent;
//Shows the window and returns when it is closed.
return app->run(transparent);
}
transparent.h
/**
* transparent.h
*
* Code adapted from 'alphademo.c' by Mike
* (http://plan99.net/~mike/blog--now a dead link--unable to find it.)
* as modified by karlphillip for StackExchange:
* (https://stackoverflow.com/questions/3908565/how-to-make-gtk-window-background-transparent)
* Re-worked for Gtkmm 3.0 by Louis Melahn, L.C. January 31, 2014.
*/
#ifndef TRANSPARENT_H_
#define TRANSPARENT_H_
#include <iostream>
#include <gtk/gtk.h>
#include <gtkmm/window.h>
#include <gtkmm/button.h>
#include <gtkmm/alignment.h>
class Transparent : public Gtk::Window
{
private:
std::string _buttonLabel;
public:
Transparent();
void set_visual(Glib::RefPtr<Gdk::Visual> visual);
virtual ~Transparent();
protected:
// Signal handlers:
// Note that on_draw is actually overriding a virtual function
// from the Gtk::Window class. I set it as virtual here in case
// someone wants to override it again in a derived class.
void on_button_clicked();
virtual bool on_draw(const ::Cairo::RefPtr< ::Cairo::Context>& cr);
void on_screen_changed(const Glib::RefPtr<Gdk::Screen>& previous_screen);
bool on_window_clicked(GdkEventButton* event);
// Member widgets:
Gtk::Alignment _alignment;
Gtk::Button _button;
bool _SUPPORTS_ALPHA = false;
};
#endif /* TRANSPARENT_H_ */
transparent.cpp
/**
* transparent.cpp
*
* Code adapted from 'alphademo.c' by Mike
* (http://plan99.net/~mike/blog--now a dead link--unable to find it.)
* as modified by karlphillip for StackExchange:
* (https://stackoverflow.com/questions/3908565/how-to-make-gtk-window-background-transparent)
* Re-worked for Gtkmm 3.0 by Louis Melahn, L.C. January 31, 2014.
*/
#include "transparent.h"
Transparent::Transparent() :
_buttonLabel("Button1"),
_alignment(Gtk::ALIGN_START, Gtk::ALIGN_START, 0.0, 0.0), // Aligns the button.
_button(_buttonLabel) // Creates a new button with label '_buttonLabel'.
{
// Set up the top-level window.
set_title("Transparency test");
set_default_size(400,400);
set_decorated(false);
add_events(Gdk::BUTTON_PRESS_MASK);
set_position(Gtk::WIN_POS_CENTER);
set_app_paintable(true);
// Signal handlers
signal_draw().connect(sigc::mem_fun(*this, &Transparent::on_draw));
signal_screen_changed().connect(sigc::mem_fun(*this, &Transparent::on_screen_changed));
signal_button_press_event().connect(sigc::mem_fun(*this, &Transparent::on_window_clicked));
_button.signal_clicked().connect(sigc::mem_fun(*this, &Transparent::on_button_clicked));
// Widgets
on_screen_changed(get_screen());
// This will add the aligner.
add(_alignment);
// Now pack the button into the aligner.
_alignment.add(_button);
// Set up the button
_button.set_size_request(100, 100);
// Show the window and all its children.
show_all();
}
Transparent::~Transparent()
{
}
void Transparent::on_button_clicked()
{
std::cout << "The button '" << _buttonLabel << "' was pressed." << std::endl;
}
bool Transparent::on_draw(const Cairo::RefPtr<Cairo::Context>& cr)
{
cr->save();
if (_SUPPORTS_ALPHA) {
cr->set_source_rgba(0.5, 1.0, 0.5, 0.5); // transparent
} else {
cr->set_source_rgb(0.5, 1.0, 0.5); // opaque
}
cr->set_operator(Cairo::OPERATOR_SOURCE);
cr->paint();
cr->restore();
return Gtk::Window::on_draw(cr);
}
/**
* Checks to see if the display supports alpha channels
*/
void Transparent::on_screen_changed(const Glib::RefPtr<Gdk::Screen>& previous_screen) {
auto screen = get_screen();
auto visual = screen->get_rgba_visual();
if (!visual) {
std::cout << "Your screen does not support alpha channels!" << std::endl;
} else {
std::cout << "Your screen supports alpha channels!" << std::endl;
_SUPPORTS_ALPHA = TRUE;
}
set_visual(visual);
}
/**
* This simply adds a method which seems to be missing in Gtk::Widget,
* so I had to use Gtk+ manually.
*
* Sets the visual for 'this' (the current widget).
*/
void Transparent::set_visual(Glib::RefPtr<Gdk::Visual> visual) {
gtk_widget_set_visual(GTK_WIDGET(gobj()), visual->gobj());
}
/**
* If I click somewhere other than the button, this toggles
* between having window decorations and not having them.
*/
bool Transparent::on_window_clicked(GdkEventButton* event) {
set_decorated(!get_decorated());
return false;
}
Hope this helps!
While struggling with the same issue, I have noticed that if I call gtk_window_set_opacity() on the toplevel window after the show_all function, making the whole window (partial) transparent works for me. Give this a try:
gtk_widget_show_all ( window );
gtk_widget_set_opacity (GTK_WIDGET (window), 0.5);
Does that work for you too?