Re: Aligning widgets adjacent to a drawing area...

[Christer Palm <palm nogui se>]

David J. Singer wrote:
> On Wednesday 21 July 2004 7:30 pm, Christer Palm wrote:
>
> > gtk_widget_translate_coordinates() with values from each of the text
> > labels allocation's and the DrawingArea as the destination should do the
> > job, I guess.
>
>
> Hmmm. I've had a look at that and I can't see how it would work for my 
> problem...  

Did you even try it? It can't be much simpler...

> I've taken the liberty of attaching some code which I've been using to 
> try and figure out how to do what I want.  (it's not pretty, but it's 
> fine to prove the concept).  

OK. Here's the code modified to do what I suppose you want.

> (As a bonus question, how do I stop the text items in the table from 
> "spacing out" when the window is maximized?  I've played with the 
> pack box options, but to no avail).

I fixed that as well. Though all this is right in the tutorial. I think 
you need to RTFM + perhaps some example code and then try a bit harder.

--
Christer Palm

#include <stdio.h>
#include <stdlib.h>
#include <gtk/gtk.h>

void gui_create();
gint gui_darea_configure(GtkWidget *widget, GdkEventConfigure *event);
gboolean gui_darea_expose(GtkWidget *widget, GdkEventExpose *event);
void gui_redraw();

#define MAX_NUM_LABELS 16

GtkWidget *window;
GtkWidget *darea;
GdkPixmap *pixmap = NULL;
GtkWidget *labels[MAX_NUM_LABELS];
GtkWidget *table;

int main( int argc, char *argv[] )
{

   GtkWidget *vbox, *hbox;
   GtkWidget *toolbar, *text;
   GtkWidget *scrolled_window;
   GtkWidget *viewport;
   int i;

   gtk_init(&argc, &argv);

   /* Create the main window */
   window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
   gtk_window_set_title(GTK_WINDOW(window), "Example");
   gtk_window_set_default_size(GTK_WINDOW(window), 600, 300);

   /* Create a vbox */
   vbox = gtk_vbox_new(FALSE, 0);

   /* Add the vbox to the main window */
   gtk_container_add(GTK_CONTAINER(window), vbox);

   /* Create a scollable window and add to the vbox */
   scrolled_window = gtk_scrolled_window_new(NULL, NULL);
   gtk_container_set_border_width(GTK_CONTAINER(scrolled_window), 2);
   gtk_scrolled_window_set_policy(GTK_SCROLLED_WINDOW(scrolled_window),
                                  GTK_POLICY_AUTOMATIC, GTK_POLICY_AUTOMATIC);
   gtk_box_pack_start(GTK_BOX(vbox), scrolled_window, TRUE, TRUE, 2);

   viewport = gtk_viewport_new(NULL, NULL);
   gtk_container_add(GTK_CONTAINER(scrolled_window), viewport);

   /* Create a table  */
   table = gtk_table_new( MAX_NUM_LABELS, 2, FALSE );
   gtk_container_add(GTK_CONTAINER(viewport), table);
   gtk_table_set_row_spacings( GTK_TABLE(table), 2 );
   gtk_table_set_col_spacings( GTK_TABLE(table), 2 );
   gtk_container_border_width( GTK_CONTAINER(table), 2 );

   /* Add labels */
   for ( i = 0; i < MAX_NUM_LABELS; i++ ) {
      text = gtk_entry_new_with_max_length(20);
      labels[i] = text;
      gtk_entry_set_text(GTK_ENTRY(text), "Label");
      gtk_entry_set_width_chars(GTK_ENTRY(text), 10);
      gtk_table_attach(GTK_TABLE(table), text, 0, 1, i, i+1,
         (GtkAttachOptions)GTK_FILL, (GtkAttachOptions)0, 0, 0);
      /* Realize the widgets now so that they have an */
      /* allocation when the drawing area is configured */
      gtk_widget_realize(text);
   }

   /* Create drawing area */
   darea = gtk_drawing_area_new();
//   gtk_widget_set_usize(darea, Darea_Width , Darea_Height); /* DEBUG */
   gtk_table_attach(GTK_TABLE(table), darea, 1, 2, 0, MAX_NUM_LABELS,
      (GtkAttachOptions)(GTK_EXPAND|GTK_FILL), (GtkAttachOptions)GTK_FILL, 0, 0);

   /* Drawing area callbacks */
   g_signal_connect(G_OBJECT(darea),"configure_event",
                    G_CALLBACK(gui_darea_configure), NULL);
   g_signal_connect(G_OBJECT(darea), "expose_event",
                       G_CALLBACK(gui_darea_expose), NULL);

   gtk_widget_show_all(window);
   gtk_main();

}

gint gui_darea_configure(GtkWidget *widget, GdkEventConfigure *event)
{
   if (pixmap)
      g_object_unref(pixmap);

   /* Create backing pixmap */
   pixmap = gdk_pixmap_new( darea->window, darea->allocation.width, darea->allocation.height, -1 );
   gui_redraw();

   return TRUE;

}

gboolean gui_darea_expose(GtkWidget *widget, GdkEventExpose *event)
{

   /* Redraw backing pixmap region modified by event */
   gdk_draw_drawable( widget->window,
                      widget->style->black_gc,
                      pixmap,
                      event->area.x, event->area.y,
                      event->area.x, event->area.y,
                      event->area.width, event->area.height );
   return TRUE;

}

void gui_redraw( void )
{

   int ytop, ybot, y, i, rc;

   /* Clear pixmap */
   gdk_draw_rectangle( pixmap, darea->style->white_gc,
                       TRUE, 0, 0, darea->allocation.width, darea->allocation.height );

   for (i=0; i < MAX_NUM_LABELS; i++) {
      if (gtk_widget_translate_coordinates(labels[i], darea, 0, 0, 0, &ytop) &&
          gtk_widget_translate_coordinates(labels[i], darea, 0, labels[i]->allocation.height, 0, &ybot)) {

         y = (ytop + ybot) / 2;
         gdk_draw_line( pixmap, darea->style->black_gc, 0, y, darea->allocation.width, y );
      }
   }
}