[Kst] [Bug 121108] Kst assertion failure when line or arrow moved outside of window

[Andrew Walker]

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http://bugs.kde.org/show_bug.cgi?id=121108         




------- Additional Comments From arwalker sumusltd com  2006-02-01 23:21 -------
Propoased patch which keeps the line/arrow within the parent, thus avoiding the assert:

Index: ksttoplevelview.cpp
===================================================================
--- ksttoplevelview.cpp (revision 504684)
+++ ksttoplevelview.cpp (working copy)
 @ -37,6 +37,7  @
 #include "kstaccessibility.h"
 #include "kstdoc.h"
 #include "kstgfxmousehandler.h"
+#include "kstmath.h"
 #include "kstplotgroup.h"
 #include "kstsettings.h"
 #include "ksttimers.h"
 @ -780,12 +781,80  @
 }


+QPoint KstTopLevelView::handlePoint(bool shift, const QPoint& ptFixed, const QPoint& pos, double aspect) {
+  QPoint ptMoved = pos;
+
+  if (shift) {
+    double absAspect = fabs(aspect);
+    if (absAspect < 500.0 && (double(abs((pos.y() - ptFixed.y())/(pos.x() - ptFixed.x()))) < aspect ||
+        absAspect < 0.1)) {
+      ptMoved = QPoint(pos.x(), ptFixed.y() + int(aspect*(pos.x() - ptFixed.x())));
+    } else {
+      ptMoved = QPoint(ptFixed.x() + int((pos.y() - ptFixed.y())/aspect), pos.y());
+    }
+  }
+
+  //
+  // ensure that the point we just moved is contained by its parent...
+  //
+  QRect parentRect = _pressTarget->_parent->_geom;
+  if (parentRect.contains(ptFixed) && !parentRect.contains(ptMoved)) {
+    double gradient;
+    bool found = false;
+    int x;
+    int y;
+
+    if (!found && ptMoved.x() < parentRect.left()) {
+      gradient = double(ptMoved.y() - ptFixed.y())/double(ptMoved.x() - ptFixed.x());
+      x = parentRect.left();
+      y = ptFixed.y() + d2i(double(x - ptFixed.x()) * gradient);
+      if (y >= parentRect.top() && y <= parentRect.bottom()) {
+        found = true;
+      }
+    }
+    if (!found && ptMoved.x() > parentRect.right()) {
+      gradient = double(ptMoved.y() - ptFixed.y())/double(ptMoved.x() - ptFixed.x());
+      x = parentRect.right();
+      y = ptFixed.y() + d2i(double(x - ptFixed.x()) * gradient);
+      if (y >= parentRect.top() && y <= parentRect.bottom()) {
+        found = true;
+      }
+    }
+    if (!found && ptMoved.y() < parentRect.top()) {
+      gradient = double(ptMoved.x() - ptFixed.x())/double(ptMoved.y() - ptFixed.y());
+      y = parentRect.top();
+      x = ptFixed.x() + d2i(double(y - ptFixed.y()) * gradient);
+      if (x >= parentRect.left() && x <= parentRect.right()) {
+        found = true;
+      }
+    }
+    if (!found && ptMoved.y() > parentRect.bottom()) {
+      gradient = double(ptMoved.x() - ptFixed.x())/double(ptMoved.y() - ptFixed.y());
+      y = parentRect.bottom();
+      x = ptFixed.x() + d2i(double(y - ptFixed.y()) * gradient);
+      if (x >= parentRect.left() && x <= parentRect.right()) {
+        found = true;
+      }
+    }
+
+    if (found) {
+      ptMoved.setX(x);
+      ptMoved.setY(y);
+    }
+  }
+
+  return ptMoved;
+}
+
+
 void KstTopLevelView::pressMoveLayoutModeEndPoint(const QPoint& pos, bool shift) {
   // FIXME: remove this!!  Should not know about any specific type
   // for now we only know how to deal with lines
   if (KstViewLinePtr line = kst_cast<KstViewLine>(_pressTarget)) {
     const QRect old(_prevBand);
+    QPoint ptFixed;
     double aspect;
+
     if (line->to().x() != line->from().x()) {
       aspect = double(line->to().y() - line->from().y()) / double(line->to().x() - line->from().x());
     } else {
 @ -795,40 +864,22  @
         aspect = 1.0E300;
       }
     }
-    QPoint fromPoint, toPoint;
+
     if (_pressDirection & UP) {
-      // UP means we are on the start endpoint
-      toPoint = line->to();
-      if (shift) {
-        double absAspect = fabs(aspect);
-        if (absAspect < 500 && (double(abs((pos.y() - toPoint.y())/(pos.x() - toPoint.x()))) < aspect || absAspect < 0.1)) {
-          fromPoint = QPoint(pos.x(), toPoint.y() + int(aspect*(pos.x() - toPoint.x())));
-        } else {
-          fromPoint = QPoint(toPoint.x() + int((pos.y() - toPoint.y())/aspect), pos.y());
-        }
-      } else {
-        fromPoint = pos;
-      }
+      // UP means we are on the "from" point
+      ptFixed = line->to();
+      _prevBand.setTopLeft(handlePoint(shift, ptFixed, pos, aspect));
+      _prevBand.setBottomRight(ptFixed);
     } else if (_pressDirection & DOWN) {
-      // DOWN means we are on the end endpoint
-      fromPoint = line->from();
-      if (shift) {
-        double absAspect = fabs(aspect);
-        if (absAspect < 500 && (double(abs((pos.y() - toPoint.y())/(pos.x() - toPoint.x()))) < aspect || absAspect < 0.1)) {
-          toPoint = QPoint(pos.x(), fromPoint.y() + int(aspect*(pos.x() - fromPoint.x())));
-        } else {
-          toPoint = QPoint(fromPoint.x() + int((pos.y() - fromPoint.y())/aspect), pos.y());
-        }
-      } else {
-        toPoint = pos;
-      }
+      // DOWN means we are on the "to" point
+      ptFixed = line->from();
+      _prevBand.setTopLeft(ptFixed);
+      _prevBand.setBottomRight(handlePoint(shift, ptFixed, pos, aspect));
     } else {
-      abort();
+      assert(false);
+      return;
     }

-    _prevBand.setTopLeft(fromPoint);
-    _prevBand.setBottomRight(toPoint);
-
     if (old != _prevBand) {
       KstPainter p;
       p.begin(_w);
Index: ksttoplevelview.h
===================================================================
--- ksttoplevelview.h   (revision 504664)
+++ ksttoplevelview.h   (working copy)
 @ -98,6 +98,7  @
     void pressMove(const QPoint& pos, bool shift = false);
     void pressMoveLayoutMode(const QPoint& pos, bool shift = false);
     // helpers for pressMoveLayoutMode
+    QPoint handlePoint(bool shift, const QPoint& ptFixed, const QPoint& pos, double aspect);
     void pressMoveLayoutModeMove(const QPoint& pos, bool shift = false);
     void pressMoveLayoutModeResize(const QPoint& pos, bool shift = false);
     void pressMoveLayoutModeSelect(const QPoint& pos, bool shift = false);