Layout::moveToWidget(): send crossing events (part 2)

This patch fixes 3f74e4d60ac1 (which is partly wrong).
The idea is to avoid spurious leave/enter events, and thus prevent bugs.

  * avoid issuing spurious leave/enter events, and send the necessary ones.
  * remove the need for a workaround linkEnter() call in
    Textblock::leaveNotifyImpl().

2 files changed, 27 insertions, 8 deletions

diff --git a/dw/layout.cc b/dw/layout.cc
index e6aebc62..cf19df37 100644
--- a/dw/layout.cc
+++ b/dw/layout.cc
@@ -844,7 +844,7 @@ Widget *Layout::getWidgetAtPoint (int x, int y)
 
 /*
  * Emit the necessary crossing events, when the mouse pointer has moved to
- * the given widget.
+ * the given widget (by mouse or scrolling).
  */
 void Layout::moveToWidget (Widget *newWidgetAtPoint, ButtonState state)
 {
@@ -890,6 +890,12 @@ void Layout::moveToWidget (Widget *newWidgetAtPoint, ButtonState state)
          for (w = newWidgetAtPoint; w != ancestor; w = w->getParent ())
             track[i--] = w;
       }
+#if 0
+      MSG("Track: %s[ ", widgetAtPoint ? "" : "nil ");
+      for (i = 0; i < trackLen; i++)
+         MSG("%s%p ", i == i_a ? ">" : "", track[i]);
+      MSG("] %s\n", newWidgetAtPoint ? "" : "nil");
+#endif
 
       /* Send events to the widgets on the track */
       for (i = 0; i < trackLen; i++) {
@@ -899,10 +905,11 @@ void Layout::moveToWidget (Widget *newWidgetAtPoint, ButtonState state)
          if (i < i_a) {
             track[i]->leaveNotify (&crossingEvent);
          } else if (i == i_a) { /* ancestor */
-            if (!widgetAtPoint)
-               track[i]->enterNotify (&crossingEvent);
-            else if (!newWidgetAtPoint)
+            /* don't touch ancestor unless moving into/from NULL */
+            if (i_a == trackLen-1 && !newWidgetAtPoint)
                track[i]->leaveNotify (&crossingEvent);
+            else if (i_a == 0 && !widgetAtPoint)
+               track[i]->enterNotify (&crossingEvent);
          } else {
             track[i]->enterNotify (&crossingEvent);
          }
diff --git a/dw/textblock.cc b/dw/textblock.cc
index 045ab729..e1689ea5 100644
--- a/dw/textblock.cc
+++ b/dw/textblock.cc
@@ -536,6 +536,11 @@ bool Textblock::buttonReleaseImpl (core::EventButton *event)
    return sendSelectionEvent (core::SelectionState::BUTTON_RELEASE, event);
 }
 
+/*
+ * Handle motion inside the widget
+ * (special care is necessary when switching from another widget,
+ *  because hoverLink and hoverTooltip are meaningless then).
+ */
 bool Textblock::motionNotifyImpl (core::EventMotion *event)
 {
    if (event->state & core::BUTTON1_MASK)
@@ -557,6 +562,7 @@ bool Textblock::motionNotifyImpl (core::EventMotion *event)
          hoverLink = style->x_link;
          hoverTooltip = style->x_tooltip;
       }
+
       // Show/hide tooltip
       if (tooltipOld != hoverTooltip) {
          if (tooltipOld)
@@ -566,21 +572,27 @@ bool Textblock::motionNotifyImpl (core::EventMotion *event)
       } else if (hoverTooltip)
          hoverTooltip->onMotion ();
 
-      if (hoverLink != linkOld)
+      _MSG("tb=%p word=%p linkOld=%d hoverLink=%d\n",
+          this, word, linkOld, hoverLink);
+      if (hoverLink != linkOld) {
+         /* LinkEnter with hoverLink == -1 is the same as LinkLeave */
          return layout->emitLinkEnter (this, hoverLink, -1, -1, -1);
-      else
+      } else {
          return hoverLink != -1;
+      }
    }
 }
 
 void Textblock::enterNotifyImpl (core::EventCrossing *event)
 {
+   _MSG(" tb=%p, ENTER NotifyImpl\n", this);
+   /* reset hoverLink so linkEnter is detected */
+   hoverLink = -2;
 }
 
 void Textblock::leaveNotifyImpl (core::EventCrossing *event)
 {
-   hoverLink = -1;
-   (void) layout->emitLinkEnter (this, hoverLink, -1, -1, -1);
+   _MSG(" tb=%p, LEAVE NotifyImpl\n", this);
    if (hoverTooltip) {
       hoverTooltip->onLeave();
       hoverTooltip = NULL;