gui/graph_displayer_canvas-zoom.cc
author ladanyi
Fri, 14 Apr 2006 15:05:51 +0000
changeset 2049 a9933b493198
parent 1777 a70cee06ae9c
permissions -rwxr-xr-x
bugfix
     1 #include "graph_displayer_canvas.h"
     2 #include <cmath>
     3 
     4 void GraphDisplayerCanvas::zoomIn()
     5 {
     6   set_pixels_per_unit(
     7       (1.0 + (double) zoom_step / 100.0) * get_pixels_per_unit());
     8 }
     9 
    10 void GraphDisplayerCanvas::zoomOut()
    11 {
    12   set_pixels_per_unit(
    13       (1.0 - (double) zoom_step / 100.0) * get_pixels_per_unit());
    14 }
    15 
    16 void GraphDisplayerCanvas::zoomFit()
    17 {
    18   updateScrollRegion();
    19 
    20   // get the height and width of the canvas
    21   Gtk::Allocation a = get_allocation();
    22   int aw = a.get_width();
    23   int ah = a.get_height();
    24 
    25   // get the bounding box of the graph
    26   update_now();
    27   double x1, y1, x2, y2;
    28   root()->get_bounds(x1, y1, x2, y2);
    29 
    30   // fit the graph to the window
    31   double ppu1 = (double) aw / fabs(x2 - x1);
    32   double ppu2 = (double) ah / fabs(y2 - y1);
    33   set_pixels_per_unit((ppu1 < ppu2) ? ppu1 : ppu2);
    34 }
    35 
    36 void GraphDisplayerCanvas::zoom100()
    37 {
    38   updateScrollRegion();
    39   set_pixels_per_unit(1.0);
    40 }
    41 
    42 void GraphDisplayerCanvas::updateScrollRegion()
    43 {
    44   // get_bounds() yields something sane only when no updates are pending
    45   // and it returns a sufficient, not an exact bounding box
    46   update_now();
    47   double x1, y1, x2, y2;
    48   root()->get_bounds(x1, y1, x2, y2);
    49   set_scroll_region(x1, y1, x2, y2);
    50 }