protected int focus_end;
protected int[] focus_starts;
protected bool focus_locked;
- protected int focus_centre;
protected bool focus_layout_needed;
protected int _focus_size;
}
}
- protected int _distortion_factor;
- public int distortion_factor {
- get { return _distortion_factor; }
- set {
- _distortion_factor = value;
- focus_layout_needed = true;
- queue_draw();
- }
- }
-
protected int _label_column;
public int label_column {
get { return _label_column; }
// Defaults for properties
focus_size = 20;
- distortion_factor = 30;
label_column = 0;
cur_el = 0;
- focus_centre = 0;
focus_locked = false;
add_events(Gdk.EventMask.POINTER_MOTION_MASK
protected int el_y(int idx)
{
- // Undistorted Y
- int undy = idx * allocation.height / label_cache.length;
// Distorted position
- int pos = fisheye(undy, focus_centre, _distortion_factor, 0, allocation.height);
+ int pos = fisheye(idx);
//stderr.printf("%d %f %f\n", idx, undy, pos);
return pos;
}
{
if (label_cache.length == 0)
{
- focus_centre = 0;
focus_first = 0;
focus_end = 0;
focus_starts[0] = 0;
} else {
- // Anchor point
- focus_centre = cur_el*allocation.height/label_cache.length;
-
focus_first = cur_el > _focus_size/2 ? cur_el-_focus_size/2 : 0;
focus_end = focus_first + _focus_size;
if (focus_end >= label_cache.length) focus_end = label_cache.length;
// Compute starting positions for all items in focus
- for (int idx = focus_first; idx < focus_end; ++idx)
+ for (int idx = focus_first; idx <= focus_end; ++idx)
{
- int posprev = idx == 0 ? 0 : el_y(idx-1);
- int pos = el_y(idx);
- int posnext = idx == label_cache.length-1 ? 1 : el_y(idx+1);
- int y0 = (pos+posprev)/2;
- int y1 = (pos+posnext)/2;
-
- focus_starts[idx - focus_first] = y0;
- focus_starts[idx - focus_first + 1] = y1;
+ focus_starts[idx - focus_first] = el_y(idx);
}
}
focus_layout_needed = false;
}
}
- /*
- * The following function is adapted from Prefuse's FisheyeDistortion.java.
- *
- * A relevant annotation from Prefuse:
- *
- * For more details on this form of transformation, see Manojit Sarkar and
- * Marc H. Brown, "Graphical Fisheye Views of Graphs", in Proceedings of
- * CHI'92, Human Factors in Computing Systems, p. 83-91, 1992. Available
- * online at <a href="http://citeseer.ist.psu.edu/sarkar92graphical.html">
- * http://citeseer.ist.psu.edu/sarkar92graphical.html</a>.
- */
-
- /*
- * Distorts an item's coordinate.
- * @param x the undistorted coordinate
- * @param coordinate of the anchor or focus point
- * @param d disortion factor
- * @param min the beginning of the display
- * @param max the end of the display
- * @return the distorted coordinate
- */
- private int fisheye(int x, int a, int d, int min, int max)
- {
- if ( d != 0 ) {
- bool left = x<a;
- double v;
- int m = (left ? a-min : max-a);
- if ( m == 0 ) m = max-min;
- v = (double)(x - a).abs() / m;
- v = (double)(d+1)/(d+(1/v));
- return (int)Math.round((left?-1:1)*m*v + a);
- } else {
- return x;
- }
- }
+ /*
+ * The following function is adapted from Prefuse's FisheyeDistortion.java.
+ *
+ * A relevant annotation from Prefuse:
+ *
+ * For more details on this form of transformation, see Manojit Sarkar and
+ * Marc H. Brown, "Graphical Fisheye Views of Graphs", in Proceedings of
+ * CHI'92, Human Factors in Computing Systems, p. 83-91, 1992. Available
+ * online at <a href="http://citeseer.ist.psu.edu/sarkar92graphical.html">
+ * http://citeseer.ist.psu.edu/sarkar92graphical.html</a>.
+ */
+
+ /*
+ * Distorts an item's coordinate.
+ * @param x the undistorted coordinate
+ * @param coordinate of the anchor or focus point
+ * @param d disortion factor
+ * @param min the beginning of the display
+ * @param max the end of the display
+ * @return the distorted coordinate
+ */
+ private int fisheye(int idx)
+ {
+ // Autocompute distortion factor
+ // 20 is the pixel size of the item at centre of focus
+ double d = label_cache.length * 20 / allocation.height;
+ if ( d <= 1 )
+ return idx * allocation.height / label_cache.length;
+
+ double a = (double)cur_el * allocation.height / label_cache.length;
+ double x = (double)idx * allocation.height / label_cache.length;
+ double max = (double)allocation.height;
+
+ if (idx < cur_el)
+ {
+ double m = a;
+ if ( m == 0 ) m = max;
+ double v = (double)(a - x) / m;
+ v = (double)(d+1)/(d+(1/v));
+ return (int)Math.round(a - m*v);
+ } else {
+ double m = max-a;
+ if ( m == 0 ) m = max;
+ double v = (double)(x - a) / m;
+ v = (double)(d+1)/(d+(1/v));
+ return (int)Math.round(a + m*v);
+ }
+ }
}
public class Fisheye : Gtk.Window