[gimp] Bug 598454 - Improve visual feedback for Free Select Tool handles

[Martin Nordholts <martinn src gnome org>]

commit c331d5f9eb4f1c967607e1fe3aa28c13185f81cb
Author: Martin Nordholts <martinn src gnome org>
Date:   Mon Dec 21 22:24:26 2009 +0100

    Bug 598454 - Improve visual feedback for Free Select Tool handles
    
    Highlight the handle for the first vertex in the Free Select Tool even
    with button1 down, since releasing the button on the first point will
    close the polygon, so it's a significant state which we must give
    feedback for.

 app/tools/gimpfreeselecttool.c |   51 ++++++++++++++++++++++++++++++++-------
 1 files changed, 42 insertions(+), 9 deletions(-)
---
diff --git a/app/tools/gimpfreeselecttool.c b/app/tools/gimpfreeselecttool.c
index 4d056ea..2484c85 100644
--- a/app/tools/gimpfreeselecttool.c
+++ b/app/tools/gimpfreeselecttool.c
@@ -351,7 +351,7 @@ gimp_free_select_tool_should_close (GimpFreeSelectTool *fst,
   gdouble                    dist         = G_MAXDOUBLE;
 
   if (priv->polygon_modified       ||
-      priv->n_segment_indices <= 1 ||
+      priv->n_segment_indices <= 0 ||
       GIMP_TOOL (fst)->display == NULL)
     return FALSE;
 
@@ -1515,27 +1515,60 @@ gimp_free_select_tool_active_modifier_key (GimpTool        *tool,
                                                        display);
 }
 
+/**
+ * gimp_free_select_tool_draw:
+ * @draw_tool:
+ *
+ * Draw the line segments and handles around segment vertices, the
+ * latter if the they are in proximity to cursor.
+ **/
 static void
 gimp_free_select_tool_draw (GimpDrawTool *draw_tool)
 {
-  GimpFreeSelectTool        *fst  = GIMP_FREE_SELECT_TOOL (draw_tool);
-  GimpFreeSelectToolPrivate *priv = GET_PRIVATE (fst);
-  GimpTool                  *tool = GIMP_TOOL (draw_tool);
-
+  GimpFreeSelectTool        *fst                   = GIMP_FREE_SELECT_TOOL (draw_tool);
+  GimpFreeSelectToolPrivate *priv                  = GET_PRIVATE (fst);
+  GimpTool                  *tool                  = GIMP_TOOL (draw_tool);
+  gboolean                   hovering_first_point  = FALSE;
+  gboolean                   handles_wants_to_show = FALSE;
+  GimpCoords                 coords                = { priv->last_coords.x,
+                                                       priv->last_coords.y,
+                                                       /* pad with 0 */ };
   if (! tool->display)
     return;
 
+  hovering_first_point =
+    gimp_free_select_tool_should_close (fst,
+                                        tool->display,
+                                        NO_CLICK_TIME_AVAILABLE,
+                                        &coords);
   gimp_draw_tool_draw_lines (draw_tool,
                              priv->points, priv->n_points,
                              FALSE, FALSE);
 
-  /* Draw handles around segment vertices in the proximity */
-  if (! priv->button1_down &&
+  /* We always show the handle for the first point, even with button1
+   * down, since releasing the button on the first point will close
+   * the polygon, so it's a significant state which we must give
+   * feedback for
+   */
+  handles_wants_to_show = (hovering_first_point ||
+                           ! priv->button1_down);
+
+  if (handles_wants_to_show &&
       ! priv->supress_handles)
     {
-      gint i;
+      gint i = 0;
+      gint n = 0;
 
-      for (i = 0; i < priv->n_segment_indices; i++)
+      /* If the first point is hovered while button1 is held down,
+       * only draw the first handle, the other handles are not
+       * relevant (see comment a few lines up)
+       */
+      if (priv->button1_down && hovering_first_point)
+        n = MIN (priv->n_segment_indices, 1);
+      else
+        n = priv->n_segment_indices;
+
+      for (i = 0; i < n; i++)
         {
           GimpVector2   *point       = NULL;
           gdouble        dist        = 0.0;