[lazarus] TCanvas
Payne Thomas E CNIN
payne_t at crane.navy.mil
Wed Jul 21 12:55:12 EDT 1999
the specific examples are provided below: The print statements are included
to show the problem.
Tom
> -----Original Message-----
> From: Payne Thomas E CNIN [mailto:payne_t at crane.navy.mil]
> Sent: Wednesday, July 21, 1999 11:15 AM [Payne Thomas E CNIN]
> To: 'lazarus at miraclec.com'
> Subject: RE: [lazarus] TCanvas
>
>
> I have been sticking with the examples under GTK, and have found some
> problems with scribble-simple (section 23) that I belive are with the GDK
> port to FPC.
>
> I have placed debugging writes in pascal and printfs in C, and am getting
> very different numbers.
>
> I was specifically looking at (PGdkEventExpose)Event^.area.height in the
> expose_event function
> & (PGdkEventMotion)Event^.state in motion_notify_event
>
> I need some help beyond this point!!!
>
> Tom
------------------------------------------------------
/* example-start scribble-simple scribble-simple.c */
/* GTK - The GIMP Toolkit
* Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh
MacDonald
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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 Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
compile under linux using
gcc `gtk-config --cflags` scribble-simple.c -o scribble-simple
`gtk-config --libs`
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
*/
#include <gtk/gtk.h>
/* Backing pixmap for drawing area */
static GdkPixmap *pixmap = NULL;
/* Create a new backing pixmap of the appropriate size */
static gint
configure_event (GtkWidget *widget, GdkEventConfigure *event)
{
if (pixmap)
gdk_pixmap_unref(pixmap);
pixmap = gdk_pixmap_new(widget->window,
widget->allocation.width,
widget->allocation.height,
-1);
gdk_draw_rectangle (pixmap,
widget->style->white_gc,
TRUE,
0, 0,
widget->allocation.width,
widget->allocation.height);
return TRUE;
}
/* Redraw the screen from the backing pixmap */
static gint
expose_event (GtkWidget *widget, GdkEventExpose *event)
{
printf("Expose Event: x= %d y= %d W= %d H= %d \n",
(gint)event->area.x,(gint)event->area.y,
(gint)event->area.width, (gint)event->area.height);
gdk_draw_pixmap(widget->window,
widget->style->fg_gc[GTK_WIDGET_STATE (widget)],
pixmap,
event->area.x, event->area.y,
event->area.x, event->area.y,
event->area.width, event->area.height);
return FALSE;
}
/* Draw a rectangle on the screen */
static void
draw_brush (GtkWidget *widget, gdouble x, gdouble y)
{
GdkRectangle update_rect;
update_rect.x = x - 5;
update_rect.y = y - 5;
update_rect.width = 10;
update_rect.height = 10;
gdk_draw_rectangle (pixmap,
widget->style->black_gc,
TRUE,
update_rect.x, update_rect.y,
update_rect.width, update_rect.height);
gtk_widget_draw (widget, &update_rect);
}
static gint
button_press_event (GtkWidget *widget, GdkEventButton *event)
{
if (event->button == 1 && pixmap != NULL)
draw_brush (widget, event->x, event->y);
return TRUE;
}
static gint
motion_notify_event (GtkWidget *widget, GdkEventMotion *event)
{
int x, y;
GdkModifierType state;
if (event->is_hint)
gdk_window_get_pointer (event->window, &x, &y, &state);
else
{
x = event->x;
y = event->y;
state = event->state;
}
printf ("Motion_notify_event: state= %d mask=
%d\n",(gint)state,(gint)GDK_BUTTON1_MASK);
if (state & GDK_BUTTON1_MASK && pixmap != NULL)
draw_brush (widget, x, y);
return TRUE;
}
void
quit ()
{
gtk_exit (0);
}
int
main (int argc, char *argv[])
{
GtkWidget *window;
GtkWidget *drawing_area;
GtkWidget *vbox;
GtkWidget *button;
gtk_init (&argc, &argv);
window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
gtk_widget_set_name (window, "Test Input");
vbox = gtk_vbox_new (FALSE, 0);
gtk_container_add (GTK_CONTAINER (window), vbox);
gtk_widget_show (vbox);
gtk_signal_connect (GTK_OBJECT (window), "destroy",
GTK_SIGNAL_FUNC (quit), NULL);
/* Create the drawing area */
drawing_area = gtk_drawing_area_new ();
gtk_drawing_area_size (GTK_DRAWING_AREA (drawing_area), 200, 200);
gtk_box_pack_start (GTK_BOX (vbox), drawing_area, TRUE, TRUE, 0);
gtk_widget_show (drawing_area);
/* Signals used to handle backing pixmap */
gtk_signal_connect (GTK_OBJECT (drawing_area), "expose_event",
(GtkSignalFunc) expose_event, NULL);
gtk_signal_connect (GTK_OBJECT(drawing_area),"configure_event",
(GtkSignalFunc) configure_event, NULL);
/* Event signals */
gtk_signal_connect (GTK_OBJECT (drawing_area),
"motion_notify_event",
(GtkSignalFunc) motion_notify_event, NULL);
gtk_signal_connect (GTK_OBJECT (drawing_area),
"button_press_event",
(GtkSignalFunc) button_press_event, NULL);
gtk_widget_set_events (drawing_area, GDK_EXPOSURE_MASK
| GDK_LEAVE_NOTIFY_MASK
| GDK_BUTTON_PRESS_MASK
| GDK_POINTER_MOTION_MASK
| GDK_POINTER_MOTION_HINT_MASK);
/* .. And a quit button */
button = gtk_button_new_with_label ("Quit");
gtk_box_pack_start (GTK_BOX (vbox), button, FALSE, FALSE, 0);
gtk_signal_connect_object (GTK_OBJECT (button), "clicked",
GTK_SIGNAL_FUNC (gtk_widget_destroy),
GTK_OBJECT (window));
gtk_widget_show (button);
gtk_widget_show (window);
gtk_main ();
return 0;
}
/* example-end */
---------------------------------------------------------------
program scribblesimple;
uses
glib,Gdk,Gtk;
{ Backing pixmap for drawing area }
const
pixmap : PGdkPixmap = NIL;
{ Create a new backing pixmap of the appropriate size }
function configure_event (widget : PGtkWidget; event:
PGdkEventConfigure): gint; cdecl;
begin
if pixmap<>NIL then
gdk_pixmap_unref(pixmap);
pixmap := gdk_pixmap_new(widget^.window,
widget^.allocation.width,
widget^.allocation.height,
-1);
writeln('Got to configure_event');
if pixmap = Nil then writeln('Nil Pixmap');
gdk_draw_rectangle (pixmap,
PGtkStyle(widget^.thestyle)^.white_gc,
gint(true),
0, 0,
widget^.allocation.width,
widget^.allocation.height);
configure_event := ord(TRUE);
end;
{ Redraw the screen from the backing pixmap }
function expose_event (widget : PGtkWidget ; event :
PGdkEventExpose ) : gint; cdecl;
begin
writeln('Expose_event: x =',event^.area.x,' y= ',event^.area.y,
' width= ',event^.area.width,' height=
',event^.area.height);
if pixmap = Nil then writeln('Nil Pixmap');
gdk_draw_pixmap(widget^.window,
PGtkStyle(widget^.thestyle)^.fg_gc[gtk_WIDGET_STATE (widget)],
pixmap,
event^.area.x, event^.area.y,
event^.area.x, event^.area.y,
event^.area.width, event^.area.height);
expose_event:= ord(FALSE);
end;
{ Draw a rectangle on the screen }
procedure draw_brush (widget : PGtkWidget ; x, y: gint16);
var update_rect : TGdkRectangle;
begin
update_rect.x := x - 5;
update_rect.y := y - 5;
update_rect.width := 10;
update_rect.height := 10;
if pixmap = Nil then
writeln('The style
',PGtkStyle(widget^.thestyle)^.white_gc^.dummy_var);
gdk_draw_rectangle (pixmap,
PGtkStyle(widget^.thestyle)^.black_gc,
gint(true),
update_rect.x, update_rect.y,
update_rect.width, update_rect.height);
gtk_widget_draw (widget, @update_rect);
end;
function button_press_event (widget : PGtkWidget ; event:
PGdkEventButton ) : gint; cdecl;
begin
writeln('Got to button_press_event');
if pixmap = Nil then writeln('Nil Pixmap');
if (event^.button = 1) and (pixmap <> NIL) then begin
draw_brush (widget, trunc(event^.x), trunc(event^.y));
end;
button_press_event := ord(TRUE);
end;
function motion_notify_event (widget : PGtkWidget ; event:
PGdkEventMotion ) : gint; cdecl;
var x, y : gint ;
state : guint;
begin
if pixmap = Nil then writeln('Nil Pixmap in motion_notify_event');
if (event^.is_hint<>0) then begin
gdk_window_get_pointer (event^.window, @x, @y, @state);
end else begin
x := trunc(event^.x);
y := trunc(event^.y);
state := event^.state;
end;
writeln('Motion_notify_event: state = ',state,' mask=
',gdk_BUTTON1_MASK);
//if ((state {and gdk_BUTTON1_MASK)<}>0) and (pixmap <> NIL) then
if (state >0) and (pixmap <> NIL) then
begin
//writeln('Continue to draw');
draw_brush (widget, x, y);
end;
motion_notify_event := ord(TRUE);
end;
procedure quit;
begin
gtk_exit (0);
end;
var window, drawing_area, vbox, button : PGtkWidget;
begin
gtk_init (@argc, @argv);
//gtk_rc_init;
window := gtk_window_new (gtk_WINDOW_TOPLEVEL);
gtk_widget_set_name (window, 'Test Input');
vbox := gtk_vbox_new (false, 0);
gtk_container_add (PGtkCONTAINER (window), vbox);
gtk_widget_show (vbox);
gtk_signal_connect (PGtkOBJECT (window), 'destroy',
gtk_SIGNAL_FUNC (@quit), NIL);
{ Create the drawing area }
drawing_area := gtk_drawing_area_new ();
gtk_drawing_area_size (PGtkDRAWINGAREA (drawing_area), 200, 200);
gtk_box_pack_start (PGtkBOX (vbox), drawing_area, true, true, 0);
gtk_widget_show (drawing_area);
{ Signals used to handle backing pixmap }
gtk_signal_connect (PGtkOBJECT (drawing_area), 'expose_event',
gtk_SIGNAL_FUNC (@expose_event), NIL);
gtk_signal_connect (PGtkOBJECT(drawing_area),'configure_event',
gtk_SIGNAL_FUNC (@configure_event), NIL);
{ Event signals }
gtk_signal_connect (PGtkOBJECT (drawing_area),
'motion_notify_event',
gtk_SIGNAL_FUNC (@motion_notify_event), NIL);
gtk_signal_connect (PGtkOBJECT (drawing_area),
'button_press_event',
gtk_SIGNAL_FUNC (@button_press_event), NIL);
gtk_widget_set_events (drawing_area, gdk_EXPOSURE_MASK
or gdk_LEAVE_NOTIFY_MASK
or gdk_BUTTON_PRESS_MASK
or gdk_POINTER_MOTION_MASK
or gdk_POINTER_MOTION_HINT_MASK);
{ .. And a quit button }
button := gtk_button_new_with_label ('Quit');
gtk_box_pack_start (PGtkBOX (vbox), button, false, false, 0);
gtk_signal_connect_object (PGtkOBJECT (button), 'clicked',
gtk_SIGNAL_FUNC (@gtk_widget_destroy),
PGtkOBJECT (window));
gtk_widget_show (button);
gtk_widget_show (window);
gtk_main ();
end.
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