split out the ComboBox code that determines the positioning of subwidgets

and re-use it to get a better calculation of the optimal size of a
widget, rather than taking the current position of the subedit

the upshot of this is that with CTL and/or CJK mode enabled in...
a) calc, then the format->cells font dialog doesn't have squashed font size and
font style listboxes
b) writer, the 10.5 default size for CJK doesn't have part of the .5 clipped
off it

the calcComboBoxDropDownComponentBounds code should be entirely equivalent
to the existing ::Resize calculation given the same input, we just call
it with effectively unbounded available size in the GetOptimalSize case
to find the desired margins around the subedit field

(cherry picked from commit d19eab221f168aed12249ffc8a36a9f1aca5a94e)

Change-Id: I85cb3ff98f23d21d7cfdcc28188e36616a19b5e8
Reviewed-on: https://gerrit.libreoffice.org/1657
Reviewed-by: Noel Power <noel.power@suse.com>
Tested-by: Noel Power <noel.power@suse.com>

2 files changed, 73 insertions, 45 deletions

diff --git a/vcl/inc/vcl/combobox.hxx b/vcl/inc/vcl/combobox.hxx
index d1704dcc9efe..72478c59a713 100644
--- a/vcl/inc/vcl/combobox.hxx
+++ b/vcl/inc/vcl/combobox.hxx
@@ -50,9 +50,20 @@ private:
     Link                        maSelectHdl;
     Link                        maDoubleClickHdl;
 
+    struct ComboBoxBounds
+    {
+        Point aSubEditPos;
+        Size aSubEditSize;
+
+        Point aButtonPos;
+        Size aButtonSize;
+    };
+
 private:
     SAL_DLLPRIVATE void     ImplInitComboBoxData();
     SAL_DLLPRIVATE void     ImplUpdateFloatSelection();
+    SAL_DLLPRIVATE ComboBoxBounds calcComboBoxDropDownComponentBounds(
+        const Size &rOutSize, const Size &rBorderOutSize) const;
 
     DECL_DLLPRIVATE_LINK(   ImplSelectHdl, void* );
     DECL_DLLPRIVATE_LINK(   ImplCancelHdl, void* );
diff --git a/vcl/source/control/combobox.cxx b/vcl/source/control/combobox.cxx
index a0f8982e9ec6..389929c34b53 100644
--- a/vcl/source/control/combobox.cxx
+++ b/vcl/source/control/combobox.cxx
@@ -597,50 +597,10 @@ void ComboBox::Resize()
     Size aOutSz = GetOutputSizePixel();
     if( IsDropDownBox() )
     {
-        long    nTop = 0;
-        long    nBottom = aOutSz.Height();
-
-        Window *pBorder = GetWindow( WINDOW_BORDER );
-        ImplControlValue aControlValue;
-        Point aPoint;
-        Rectangle aContent, aBound;
-
-        // use the full extent of the control
-        Rectangle aArea( aPoint, pBorder->GetOutputSizePixel() );
-
-        if ( GetNativeControlRegion(CTRL_COMBOBOX, PART_BUTTON_DOWN,
-                aArea, 0, aControlValue, rtl::OUString(), aBound, aContent) )
-        {
-            // convert back from border space to local coordinates
-            aPoint = pBorder->ScreenToOutputPixel( OutputToScreenPixel( aPoint ) );
-            aContent.Move(-aPoint.X(), -aPoint.Y());
-
-            mpBtn->setPosSizePixel( aContent.Left(), nTop, aContent.getWidth(), (nBottom-nTop) );
-
-            // adjust the size of the edit field
-            if ( GetNativeControlRegion(CTRL_COMBOBOX, PART_SUB_EDIT,
-                        aArea, 0, aControlValue, rtl::OUString(), aBound, aContent) )
-            {
-                // convert back from border space to local coordinates
-                aContent.Move(-aPoint.X(), -aPoint.Y());
-
-                // use the themes drop down size
-                mpSubEdit->SetPosSizePixel( aContent.TopLeft(), aContent.GetSize() );
-            }
-            else
-            {
-                // use the themes drop down size for the button
-                aOutSz.Width() -= aContent.getWidth();
-                mpSubEdit->SetSizePixel( aOutSz );
-            }
-        }
-        else
-        {
-            long nSBWidth = GetSettings().GetStyleSettings().GetScrollBarSize();
-            nSBWidth = CalcZoom( nSBWidth );
-            mpSubEdit->SetPosSizePixel( Point( 0, 0 ), Size( aOutSz.Width() - nSBWidth, aOutSz.Height() ) );
-            mpBtn->setPosSizePixel( aOutSz.Width() - nSBWidth, nTop, nSBWidth, (nBottom-nTop) );
-        }
+        ComboBoxBounds aBounds(calcComboBoxDropDownComponentBounds(aOutSz,
+            GetWindow(WINDOW_BORDER)->GetOutputSizePixel()));
+        mpSubEdit->SetPosSizePixel(aBounds.aSubEditPos, aBounds.aSubEditSize);
+        mpBtn->SetPosSizePixel(aBounds.aButtonPos, aBounds.aButtonSize);
     }
     else
     {
@@ -1106,12 +1066,15 @@ Size ComboBox::CalcMinimumSize() const
     else
     {
         aSz.Height() = Edit::CalcMinimumSizeForText(GetText()).Height();
+
         aSz.Width() = mpImplLB->GetMaxEntryWidth();
         aSz.Width() += getMaxWidthScrollBarAndDownButton();
+        ComboBoxBounds aBounds(calcComboBoxDropDownComponentBounds(
+            Size(0xFFFF, 0xFFFF), Size(0xFFFF, 0xFFFF)));
+        aSz.Width() += aBounds.aSubEditPos.X()*2;
     }
 
     aSz.Width() += ImplGetExtraOffset() * 2;
-    aSz.Width() += mpSubEdit->GetPosPixel().X();
 
     aSz = CalcWindowSize( aSz );
     return aSz;
@@ -1529,4 +1492,58 @@ long ComboBox::GetIndexForPoint( const Point& rPoint, sal_uInt16& rPos ) const
     return nIndex;
 }
 
+ComboBox::ComboBoxBounds ComboBox::calcComboBoxDropDownComponentBounds(const Size &rOutSz,
+    const Size &rBorderOutSz) const
+{
+    ComboBoxBounds aBounds;
+
+    long    nTop = 0;
+    long    nBottom = rOutSz.Height();
+
+    Window *pBorder = GetWindow( WINDOW_BORDER );
+    ImplControlValue aControlValue;
+    Point aPoint;
+    Rectangle aContent, aBound;
+
+    // use the full extent of the control
+    Rectangle aArea( aPoint, rBorderOutSz );
+
+    if ( GetNativeControlRegion(CTRL_COMBOBOX, PART_BUTTON_DOWN,
+            aArea, 0, aControlValue, rtl::OUString(), aBound, aContent) )
+    {
+        // convert back from border space to local coordinates
+        aPoint = pBorder->ScreenToOutputPixel( OutputToScreenPixel( aPoint ) );
+        aContent.Move(-aPoint.X(), -aPoint.Y());
+
+        aBounds.aButtonPos = Point(aContent.Left(), nTop);
+        aBounds.aButtonSize = Size(aContent.getWidth(), (nBottom-nTop));
+
+        // adjust the size of the edit field
+        if ( GetNativeControlRegion(CTRL_COMBOBOX, PART_SUB_EDIT,
+                    aArea, 0, aControlValue, rtl::OUString(), aBound, aContent) )
+        {
+            // convert back from border space to local coordinates
+            aContent.Move(-aPoint.X(), -aPoint.Y());
+
+            // use the themes drop down size
+            aBounds.aSubEditPos = aContent.TopLeft();
+            aBounds.aSubEditSize = aContent.GetSize();
+        }
+        else
+        {
+            // use the themes drop down size for the button
+            aBounds.aSubEditSize = Size(rOutSz.Width() - aContent.getWidth(), rOutSz.Height());
+        }
+    }
+    else
+    {
+        long nSBWidth = GetSettings().GetStyleSettings().GetScrollBarSize();
+        nSBWidth = CalcZoom( nSBWidth );
+        aBounds.aSubEditSize = Size(rOutSz.Width() - nSBWidth, rOutSz.Height());
+        aBounds.aButtonPos = Point(rOutSz.Width() - nSBWidth, nTop);
+        aBounds.aButtonSize = Size(nSBWidth, (nBottom-nTop));
+    }
+    return aBounds;
+}
+
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */