make SalLayoutGlyphs work with MultiSalLayout

Code that needs to lay out texts repeatedly can cache the result
of SalLayout::GetGlyphs() can reuse it. But GetGlyphs() returns
nullptr for MultiSalLayout, so caching for it doesn't work. Worse
still, it actually increases the number of layout calls, because
there's the initial layout for caching and then each call
will need to do the layout again because of the nullptr that's
not cached.

This commit changes SalLayoutGlyphs to possibly include multiple
SalLayoutGlyphsImpl objects, one for each SalLayout handled
by MultiSalLayout. Changes include making GenericSalLayout
work directly with the Impl class, which avoids an indirection
and simplifies code.

Change-Id: Ic4b19934a8a06d4955b51527fe3777c5e91107b2
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/112590
Tested-by: Jenkins
Reviewed-by: Luboš Luňák <l.lunak@collabora.com>

2 files changed, 9 insertions, 13 deletions

diff --git a/vcl/source/window/menuitemlist.cxx b/vcl/source/window/menuitemlist.cxx
index 6921e6208118..a9903447c748 100644
--- a/vcl/source/window/menuitemlist.cxx
+++ b/vcl/source/window/menuitemlist.cxx
@@ -52,12 +52,8 @@ SalLayoutGlyphs* MenuItemData::GetTextGlyphs(const OutputDevice* pOutputDevice)
     if (!pLayout)
         return nullptr;
 
-    const SalLayoutGlyphs* pGlyphs = pLayout->GetGlyphs();
-    if (!pGlyphs)
-        return nullptr;
-
     // Remember the calculation result.
-    aTextGlyphs = *pGlyphs;
+    aTextGlyphs = pLayout->GetGlyphs();
 
     return &aTextGlyphs;
 }
diff --git a/vcl/source/window/status.cxx b/vcl/source/window/status.cxx
index e24a76da30c1..e3c193609bd3 100644
--- a/vcl/source/window/status.cxx
+++ b/vcl/source/window/status.cxx
@@ -398,8 +398,8 @@ void StatusBar::ImplDrawItem(vcl::RenderContext& rRenderContext, bool bOffScreen
             pLayoutCache = pItem->mxLayoutCache.get();
         }
 
-        const SalLayoutGlyphs* pGlyphs = pLayoutCache ? pLayoutCache->GetGlyphs() : nullptr;
-        Size aTextSize(rRenderContext.GetTextWidth(pItem->maText,0,-1,nullptr,pGlyphs), rRenderContext.GetTextHeight());
+        const SalLayoutGlyphs glyphs = pLayoutCache ? pLayoutCache->GetGlyphs() : SalLayoutGlyphs();
+        Size aTextSize(rRenderContext.GetTextWidth(pItem->maText,0,-1,nullptr,&glyphs), rRenderContext.GetTextHeight());
         Point aTextPos = ImplGetItemTextPos(aTextRectSize, aTextSize, pItem->mnBits);
 
         if (bOffScreen)
@@ -408,7 +408,7 @@ void StatusBar::ImplDrawItem(vcl::RenderContext& rRenderContext, bool bOffScreen
                         aTextPos,
                         pItem->maText,
                         0, -1, nullptr, nullptr,
-                        pGlyphs );
+                        &glyphs );
         }
         else
         {
@@ -418,7 +418,7 @@ void StatusBar::ImplDrawItem(vcl::RenderContext& rRenderContext, bool bOffScreen
                         aTextPos,
                         pItem->maText,
                         0, -1, nullptr, nullptr,
-                        pGlyphs );
+                        &glyphs );
         }
     }
 
@@ -1139,15 +1139,15 @@ void StatusBar::SetItemText( sal_uInt16 nItemId, const OUString& rText, int nCha
     if (nCharsWidth != -1)
     {
         std::unique_ptr<SalLayout> pSalLayout = ImplLayout("0",0,-1);
-        const SalLayoutGlyphs* pGlyphs = pSalLayout ? pSalLayout->GetGlyphs() : nullptr;
-        nWidth = GetTextWidth("0",0,-1,nullptr,pGlyphs );
+        const SalLayoutGlyphs glyphs = pSalLayout ? pSalLayout->GetGlyphs() : SalLayoutGlyphs();
+        nWidth = GetTextWidth("0",0,-1,nullptr,&glyphs);
         nWidth = nWidth * nCharsWidth + nFudge;
     }
     else
     {
         std::unique_ptr<SalLayout> pSalLayout = ImplLayout(pItem->maText,0,-1);
-        const SalLayoutGlyphs* pGlyphs = pSalLayout ? pSalLayout->GetGlyphs() : nullptr;
-        nWidth = GetTextWidth( pItem->maText,0,-1,nullptr,pGlyphs ) + nFudge;
+        const SalLayoutGlyphs glyphs = pSalLayout ? pSalLayout->GetGlyphs() : SalLayoutGlyphs();
+        nWidth = GetTextWidth( pItem->maText,0,-1,nullptr,&glyphs) + nFudge;
         // Store the calculated layout.
         pItem->mxLayoutCache = std::move(pSalLayout);
     }