Resolves: tdf#97495 fix SmElementsControl tooltips

instead of setting a single tooltip for the whole
panel area, wait for a tooltip request and specify
the area to which it applies.

Which is what other widgets that have different
tooltip areas do, and maps much better to the gtk3
tooltip system which functions like that too.

Change-Id: I56f452562c3c4d9dcec4109a8ee6168f34619472

starmath/inc/ElementsDockingWindow.hxx

@@ -83,7 +83,8 @@ class SmElementsControl : public Control
 
     virtual void Paint(vcl::RenderContext& rRenderContext, const Rectangle&) override;
     virtual void MouseButtonDown(const MouseEvent& rMEvt) override;
-    virtual void MouseMove( const MouseEvent& rMEvt ) override;
+    virtual void MouseMove(const MouseEvent& rMEvt) override;
+    virtual void RequestHelp(const HelpEvent& rHEvt) override;
 
     SmDocShell*   mpDocShell;
     SmFormat      maFormat;

starmath/source/ElementsDockingWindow.cxx

@@ -28,6 +28,7 @@
 #include <svl/stritem.hxx>
 #include <sfx2/dispatch.hxx>
 #include <sfx2/sfxmodelfactory.hxx>
+#include <vcl/help.hxx>
 #include <vcl/settings.hxx>
 
 SmElement::SmElement(SmNodePointer pNode, const OUString& aText, const OUString& aHelpText) :
@@ -387,10 +388,55 @@ void SmElementsControl::Paint(vcl::RenderContext& rRenderContext, const Rectangl
     rRenderContext.Pop();
 }
 
+void SmElementsControl::RequestHelp(const HelpEvent& rHEvt)
+{
+    if (rHEvt.GetMode() & (HelpEventMode::BALLOON | HelpEventMode::QUICK))
+    {
+        SmElement* pHelpElement = mpCurrentElement;
+
+        if (!rHEvt.KeyboardActivated())
+        {
+            Point aHelpEventPos(ScreenToOutputPixel(rHEvt.GetMousePosPixel()));
+            for (size_t i = 0; i < maElementList.size() ; i++)
+            {
+                SmElement* pElement = maElementList[i].get();
+                Rectangle aRect(pElement->mBoxLocation, pElement->mBoxSize);
+                if (aRect.IsInside(aHelpEventPos))
+                {
+                    pHelpElement = pElement;
+                    break;
+                }
+            }
+        }
+
+        if (!pHelpElement)
+            return;
+
+        Rectangle aHelpRect(pHelpElement->mBoxLocation, pHelpElement->mBoxSize);
+        Point aPt = OutputToScreenPixel( aHelpRect.TopLeft() );
+        aHelpRect.Left() = aPt.X();
+        aHelpRect.Top()= aPt.Y();
+        aPt = OutputToScreenPixel( aHelpRect.BottomRight() );
+        aHelpRect.Right() = aPt.X();
+        aHelpRect.Bottom() = aPt.Y();
+
+        // get text and display it
+        OUString aStr = pHelpElement->getHelpText();
+        if (rHEvt.GetMode() & HelpEventMode::BALLOON)
+        {
+            Help::ShowBalloon(this, aHelpRect.Center(), aHelpRect, aStr);
+        }
+        else
+            Help::ShowQuickHelp(this, aHelpRect, aStr, aStr, QuickHelpFlags::CtrlText);
+        return;
+    }
+
+    Control::RequestHelp(rHEvt);
+}
+
 void SmElementsControl::MouseMove( const MouseEvent& rMouseEvent )
 {
     mpCurrentElement = nullptr;
-    OUString tooltip;
     if (Rectangle(Point(0, 0), GetOutputSizePixel()).IsInside(rMouseEvent.GetPosPixel()))
     {
         for (size_t i = 0; i < maElementList.size() ; i++)
@@ -404,17 +450,13 @@ void SmElementsControl::MouseMove( const MouseEvent& rMouseEvent )
                     mpCurrentElement = element;
                     LayoutOrPaintContents();
                     Invalidate();
-                    tooltip = element->getHelpText();
                 }
             }
         }
-    }
-    else
-    {
-        Control::MouseMove (rMouseEvent);
+        return;
     }
 
-    SetQuickHelpText(tooltip);
+    Control::MouseMove(rMouseEvent);
 }
 
 void SmElementsControl::MouseButtonDown(const MouseEvent& rMouseEvent)