tdf#142458 Set correct ScrolledWindow BorderWidth in the ctor

and keep it updated when the relevant properties that affect it change.
This avoids the problem that the borderwidth can change during "Paint"
(which is something we strongly want to avoid) since...

since:

commit f39f21d92ec83c3a5062f29dd26214fc83012c06
Date:   Thu Nov 19 11:51:13 2020 +0100

tdf#138010 (IV) VclScrolledWindow: Use actual border width

hopefully after this we can then double-check to see if we can remove
the potential change of BorderWidth during paint.

Change-Id: I2ec317d86687fdb75e6323905f6d1c3b8fc655e1
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/121615
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>

1 files changed, 40 insertions, 18 deletions

diff --git a/vcl/source/window/layout.cxx b/vcl/source/window/layout.cxx
index 6ce711bea1aa..680a650f34f2 100644
--- a/vcl/source/window/layout.cxx
+++ b/vcl/source/window/layout.cxx
@@ -1809,7 +1809,6 @@ IMPL_LINK( VclExpander, ClickHdl, CheckBox&, rBtn, void )
 VclScrolledWindow::VclScrolledWindow(vcl::Window *pParent)
     : VclBin(pParent, WB_HIDE | WB_CLIPCHILDREN | WB_AUTOHSCROLL | WB_AUTOVSCROLL | WB_TABSTOP)
     , m_bUserManagedScrolling(false)
-    , m_nBorderWidth(1)
     , m_eDrawFrameStyle(DrawFrameStyle::NONE)
     , m_eDrawFrameFlags(DrawFrameFlags::NONE)
     , m_pVScroll(VclPtr<ScrollBar>::Create(this, WB_HIDE | WB_VERT))
@@ -1827,6 +1826,18 @@ VclScrolledWindow::VclScrolledWindow(vcl::Window *pParent)
     Link<ScrollBar*,void> aLink( LINK( this, VclScrolledWindow, ScrollBarHdl ) );
     m_pVScroll->SetScrollHdl(aLink);
     m_pHScroll->SetScrollHdl(aLink);
+
+    m_nBorderWidth = CalcBorderWidth();
+}
+
+int VclScrolledWindow::CalcBorderWidth() const
+{
+    const tools::Rectangle aRect(tools::Rectangle(Point(0, 0), Size(100, 100)));
+    DecorationView aDecoView(const_cast<OutputDevice*>(GetOutDev()));
+    // don't actually draw anything, just measure what size it would be and the diff is the desired border size to reserve
+    const tools::Rectangle aContentRect = aDecoView.DrawFrame(aRect, m_eDrawFrameStyle, m_eDrawFrameFlags | DrawFrameFlags::NoDraw);
+    const auto nBorderWidth = (aRect.GetWidth() - aContentRect.GetWidth()) / 2;
+    return std::max<int>(nBorderWidth, 1);
 }
 
 void VclScrolledWindow::dispose()
@@ -2030,24 +2041,35 @@ Size VclScrolledWindow::getVisibleChildSize() const
 
 bool VclScrolledWindow::set_property(const OString &rKey, const OUString &rValue)
 {
-    if (rKey == "shadow-type")
-    {
-        // despite the style names, this looks like the best mapping
-        if (rValue == "in")
-            m_eDrawFrameStyle = DrawFrameStyle::Out;
-        else if (rValue == "out")
-            m_eDrawFrameStyle = DrawFrameStyle::In;
-        else if (rValue == "etched-in")
-            m_eDrawFrameStyle = DrawFrameStyle::DoubleOut;
-        else if (rValue == "etched-out")
-            m_eDrawFrameStyle = DrawFrameStyle::DoubleIn;
-        else if (rValue == "none")
-            m_eDrawFrameStyle = DrawFrameStyle::NONE;
-        return true;
-    }
-    else if (rKey == "name")
+    if (rKey == "shadow-type" || rKey == "name")
     {
-        m_eDrawFrameFlags = rValue == "monoborder" ? DrawFrameFlags::Mono : DrawFrameFlags::NONE;
+        if (rKey == "shadow-type")
+        {
+            // despite the style names, this looks like the best mapping
+            if (rValue == "in")
+                m_eDrawFrameStyle = DrawFrameStyle::Out;
+            else if (rValue == "out")
+                m_eDrawFrameStyle = DrawFrameStyle::In;
+            else if (rValue == "etched-in")
+                m_eDrawFrameStyle = DrawFrameStyle::DoubleOut;
+            else if (rValue == "etched-out")
+                m_eDrawFrameStyle = DrawFrameStyle::DoubleIn;
+            else if (rValue == "none")
+                m_eDrawFrameStyle = DrawFrameStyle::NONE;
+        }
+        else if (rKey == "name")
+        {
+            m_eDrawFrameFlags = rValue == "monoborder" ? DrawFrameFlags::Mono : DrawFrameFlags::NONE;
+        }
+
+        auto nBorderWidth = CalcBorderWidth();
+        if (m_nBorderWidth != nBorderWidth)
+        {
+            m_nBorderWidth = nBorderWidth;
+            queue_resize();
+        }
+
+        return true;
     }
 
     bool bRet = VclBin::set_property(rKey, rValue);