COIN-OR::LEMON - Graph Library

source: lemon-0.x/gui/graph_displayer_canvas-zoom.cc @ 1777:a70cee06ae9c

Last change on this file since 1777:a70cee06ae9c was 1777:a70cee06ae9c, checked in by Akos Ladanyi, 14 years ago

improved zooming

  • Property exe set to *
File size: 1.2 KB
Line 
1#include "graph_displayer_canvas.h"
2#include "broken_edge.h"
3#include <cmath>
4
5void GraphDisplayerCanvas::zoomIn()
6{
7  set_pixels_per_unit(
8      (1.0 + (double) zoom_step / 100.0) * get_pixels_per_unit());
9}
10
11void GraphDisplayerCanvas::zoomOut()
12{
13  set_pixels_per_unit(
14      (1.0 - (double) zoom_step / 100.0) * get_pixels_per_unit());
15}
16
17void GraphDisplayerCanvas::zoomFit()
18{
19  updateScrollRegion();
20
21  // get the height and width of the canvas
22  Gtk::Allocation a = get_allocation();
23  int aw = a.get_width();
24  int ah = a.get_height();
25
26  // get the bounding box of the graph
27  update_now();
28  double x1, y1, x2, y2;
29  root()->get_bounds(x1, y1, x2, y2);
30
31  // fit the graph to the window
32  double ppu1 = (double) aw / fabs(x2 - x1);
33  double ppu2 = (double) ah / fabs(y2 - y1);
34  set_pixels_per_unit((ppu1 < ppu2) ? ppu1 : ppu2);
35}
36
37void GraphDisplayerCanvas::zoom100()
38{
39  updateScrollRegion();
40  set_pixels_per_unit(1.0);
41}
42
43void GraphDisplayerCanvas::updateScrollRegion()
44{
45  // get_bounds() yields something sane only when no updates are pending
46  // and it returns a sufficient, not an exact bounding box
47  update_now();
48  double x1, y1, x2, y2;
49  root()->get_bounds(x1, y1, x2, y2);
50  set_scroll_region(x1, y1, x2, y2);
51}
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