source: glemon-0.x/graph_displayer_canvas-zoom.cc @ 76:76f4f2ae0e7d

#include "graph_displayer_canvas.h"
#include "broken_edge.h"
#include <cmath>

void GraphDisplayerCanvas::zoomIn()
{
  set_pixels_per_unit(
      (1.0 + (double) zoom_step / 100.0) * get_pixels_per_unit());
}

void GraphDisplayerCanvas::zoomOut()
{
  set_pixels_per_unit(
      (1.0 - (double) zoom_step / 100.0) * get_pixels_per_unit());
}

void GraphDisplayerCanvas::zoomFit()
{
  // get the height and width of the canvas
  Gtk::Allocation a = get_allocation();
  int aw = a.get_width();
  int ah = a.get_height();
  // add some space
  aw -= 5; if (aw < 0) aw = 0;
  ah -= 5; if (ah < 0) ah = 0;

  // get the bounding box of the graph
  double wx1, wy1, wx2, wy2;
  Gnome::Canvas::Item* pCanvasItem = root();
  pCanvasItem->get_bounds(wx1, wy1, wx2, wy2);

  // fit the graph to the window
  double ppu1 = (double) aw / fabs(wx2 - wx1);
  double ppu2 = (double) ah / fabs(wy2 - wy1);
  set_pixels_per_unit((ppu1 < ppu2) ? ppu1 : ppu2);
}

void GraphDisplayerCanvas::zoom100()
{
  set_pixels_per_unit(1.0);
}

void GraphDisplayerCanvas::updateScrollRegion()
{
  double wx1, wy1, wx2, wy2;
  Gnome::Canvas::Item* pCanvasItem = root();
  pCanvasItem->get_bounds(wx1, wy1, wx2, wy2);
  set_scroll_region(wx1, wy1, wx2, wy2);
}