you can find a sample program doing all of this, and more, here:
https://gitlab.com/ivor/GTK3-Cairo
On Wed, Oct 21, 2015 at 1:45 PM, Reymond Dominique <reymon...@labogeo.pf>
wrote:
> Hi all
>
>
> I am looking for an example of program with the new functions in gtk3.0,
> for zooming with the mouse inside a window containing a plot of data (XY
> type): when pressing the left button of mouse: a rectangular box appears in
> the window, that we can enlarge or decrease with the mouse.
>
> I have already made theses function in GTK2.0 that work well, but the
> passage to GTK3.0 with the cairo functions is not evident for me. In fact I
> have some difficulties to replace the old functions by the new ones in
> GTK3.0.
>
> Here are below the 3 functions to update into GTK3.0:
> press_event(), selection_event() and release_event()
>
> thank you for any help
>
> Dominique
>
> ///////////////////////////////////////////////////////////////////////
>
> /* press_event, event that occurs when the user click on the drawing area
> * left button == zoom
> * middle button == function intercepts
> * right button == axes intercepts
> */
> gboolean press_event(GtkWidget *widget, GdkEventButton *event, NZE *ps)
> {
> GdkGC *gc;
> static gulong id2;
>
> switch(event->button)
> {
> case 1: // zoom to the selection
>
> printf(" in press_event\n");
>
> // remove the motion event signal
> g_signal_handlers_disconnect_by_func(G_OBJECT(widget),
> G_CALLBACK(motion_event),
> (gpointer)ps);
>
> // store the press coordinates
> Curseur.X_down = (gint)event->x;
> Curseur.Y_down = (gint)event->y;
>
>
> //default gc of the window
> gc = gdk_gc_new(widget->window);
>
> if(ps->pixmap_zoom) g_object_unref(ps->pixmap_zoom);
>
> // create a new pixmap of a size equal to the drawing area
> ps->pixmap_zoom = gdk_pixmap_new(widget->window,
> widget->allocation.width,
> widget->allocation.height,
> -1);
>
> // deprecated
> gdk_draw_drawable(
> ps->pixmap_zoom,
> gc,
> widget->window,
> 0, 0,
> 0, 0,
> widget->allocation.width ,
> widget->allocation.height);
>
> /*
> // new code with cairo
> cairo_t *cr = gdk_cairo_create (widget->window);
> gdk_cairo_set_source_pixmap (cr,
> ps->pixmap_zoom,
> 0,
> 0);
> cairo_paint(cr);
>
> moveto3(cr,Curseur.X_down, 0);
> lineto3(cr,Curseur.X_down,widget->allocation.height);
> cairo_stroke(cr);
> */
> // connect the motion signal so we see a rectangle
> id2 = g_signal_connect( widget,
> "motion_notify_event",
> G_CALLBACK(selection_event),
> ps);
>
>
> // gdk_window_set_cursor(widget->window, cursors[event->button]);
>
> g_signal_connect(G_OBJECT(widget),
> "button_release_event",
> G_CALLBACK(release_event),
> (gpointer)ps);
> break;
> case 2: // not yet in function
> break;
> case 3: // not yet in function
> break;
> default:
> // g_assert_not_reached();
> break;
> }
>
> return FALSE;
> }
>
> //////////////////////////////////////////////////////////////////////////////////
> /////////////////////////////////////////////////////////////////////////
> /* selection_event, this callback is registered after a mouse button has
> been
> * pressed in the drawing area, it erases the ?last? rectangle and draws
> * another to represent the area the user has selected. the callback is
> * unregistered when the user releases the mouse button
> */
>
> gboolean selection_event(GtkWidget *widget, GdkEventMotion *event, NZE
> *ps)
> {
> GdkGC *gc;
>
> GdkModifierType state;
> int x,y;
>
> gc = gdk_gc_new(widget->window);
>
> gdk_window_get_pointer (event->window, &x, &y, &state);
> if (state & GDK_BUTTON1_MASK)
> {
>
> Curseur.X_end = (gint) event->x;
> Curseur.Y_end = (gint) event->y;
>
> // warning deprecated
> gdk_draw_drawable( widget->window,
> gc,
> ps->pixmap_zoom,
> 0, 0,
> 0, 0,
> widget->allocation.width,
> widget->allocation.height);
>
> // set_color(gc,colormap,60,60,60);
>
> // deprecated function
> gdk_draw_rectangle(
> widget->window,
> gc,
> FALSE,
> get_startx(Curseur), 0,
> abs(Curseur.X_down - Curseur.X_end),
> widget->allocation.height);
>
> g_object_unref(gc);
>
>
> /*
> // new code cairo: doesn't work
> cairo_t *cr = gdk_cairo_create (widget->window);
>
> // cairo_translate(cr, Curseur.X_down - Curseur.X_end,0);
> gdk_cairo_set_source_pixmap(cr, widget->window,0,0);
>
> cairo_fill(cr);
> // cairo_paint (cr);
> // cairo_stroke(cr);
>
> moveto3(cr,Curseur.X_end, 0);
> lineto3(cr,Curseur.X_end,widget->allocation.height);
> */
>
> /*
> // gdk_cairo_set_source_window(cr,widget->window,0,0);
> gdk_cairo_set_source_pixmap(cr,
> widget->window,
> 0,0);
> // new code with cairo
> cairo_set_source_rgb(cr, 0, 0, 0);
> cairo_set_line_width(cr, 1);
>
> cairo_rectangle(
> cr,
> get_startx(Curseur), 0,
> abs(Curseur.X_down - Curseur.X_end),
> widget->allocation.height);
>
> // cairo_stroke(cr);
> */
>
>
> }
> return FALSE;
> }
>
>
> ////////////////////////////////////////////////////////////////////////////
> /* release_event, event that occurs when the user releases button on the
> * drawing area
> */
> gboolean release_event(GtkWidget *widget, GdkEventButton *event, NZE *ps)
> {
> gint x_up, y_up;
> gdouble x1, x2;
>
>
>
> switch(event->button)
> {
> case 1: // zoom to the selection
>
> /* remove the selection callback, and this callback */
> g_signal_handlers_disconnect_by_func(widget,
> G_CALLBACK(release_event),
> (gpointer)ps);
> g_signal_handlers_disconnect_by_func(widget,
>
> G_CALLBACK(selection_event),(gpointer)ps);
>
> // put the normal cursor back
> // gdk_window_set_cursor(widget->window, cursors[0]);
>
> x_up = (gint)event->x;
> y_up = (gint)event->y;
>
> // check for zero width or zero height
> if(x_up == Curseur.X_down)
> {
> g_signal_connect( widget,
> "motion_notify_event",
> G_CALLBACK(motion_event),
> ps);
> return TRUE;
> }
>
> x1 = (Curseur.X_down < x_up) ?
> real_x(Curseur.X_down,ps->ideb,ps->ifin,widget->allocation.width ):
> real_x(x_up,ps->ideb,ps->ifin,widget->allocation.width);
> x2 = (Curseur.X_down > x_up) ?
> real_x(Curseur.X_down,ps->ideb,ps->ifin,widget->allocation.width ):
> real_x(x_up,ps->ideb,ps->ifin,widget->allocation.width);
> // y1 = (Curseur.Y_down > y_up) ? real_y(Curseur.Y_down) :
> real_y(y_up);
> // y2 = (Curseur.Y_down < y_up) ? real_y(Curseur.Y_down) :
> real_y(y_up);
>
>
> reDrawSingleChan(ps->zone_signal, ps);
>
>
> // g_signal_handler_unblock(widget,id_motion_event);
>
> g_signal_connect( widget,
> "motion_notify_event",
> G_CALLBACK(motion_event),
> ps);
> break;
> case 2: // not yet in function
> break;
> case 3: // not yet in function
> break;
> default:
> g_assert_not_reached();
> break;
> }
>
> return FALSE;
> }
>
>
> ///////////////////////////////////////////////////////////////////////////////
>
>
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>
>
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