Cache text layout of statusbar items

Extend lifecycle of SalLayout created by the output device.
A layout is stored for each status bar item and used as a cache.
The layout may be updated through output device method parameters.

This way it's no longer necessary to calculate the layout again and again when
painting the status bar item multiple times, provided that its text does not
change.

Change-Id: I6494c2d6b676e8f4fdda2cde6165ff0755fd4fa2
Reviewed-on: https://gerrit.libreoffice.org/38578
Reviewed-by: Tamás Bunth <btomi96@gmail.com>
Tested-by: Tamás Bunth <btomi96@gmail.com>

1 files changed, 61 insertions, 19 deletions

diff --git a/vcl/source/window/status.cxx b/vcl/source/window/status.cxx
index aa5c1f59f6e6..c4f44d8e1a4b 100644
--- a/vcl/source/window/status.cxx
+++ b/vcl/source/window/status.cxx
@@ -32,6 +32,8 @@
 #include <svdata.hxx>
 #include <window.h>
 
+#include "sallayout.hxx"
+
 #define STATUSBAR_OFFSET_X      STATUSBAR_OFFSET
 #define STATUSBAR_OFFSET_Y      2
 #define STATUSBAR_OFFSET_TEXTY  3
@@ -59,20 +61,21 @@ StatusBar::ImplData::ImplData()
 
 struct ImplStatusItem
 {
-    sal_uInt16              mnId;
-    StatusBarItemBits   mnBits;
-    long                mnWidth;
-    long                mnOffset;
-    long                mnExtraWidth;
-    long                mnX;
-    OUString            maText;
-    OUString            maHelpText;
-    OUString            maQuickHelpText;
-    OString             maHelpId;
-    void*               mpUserData;
-    bool            mbVisible;
-    OUString            maAccessibleName;
-    OUString            maCommand;
+    sal_uInt16                          mnId;
+    StatusBarItemBits                   mnBits;
+    long                                mnWidth;
+    long                                mnOffset;
+    long                                mnExtraWidth;
+    long                                mnX;
+    OUString                            maText;
+    OUString                            maHelpText;
+    OUString                            maQuickHelpText;
+    OString                             maHelpId;
+    void*                               mpUserData;
+    bool                                mbVisible;
+    OUString                            maAccessibleName;
+    OUString                            maCommand;
+    std::unique_ptr<SalLayout>          mxLayoutCache;
 };
 
 inline long ImplCalcProgressWidth( sal_uInt16 nMax, long nSize )
@@ -369,20 +372,38 @@ void StatusBar::ImplDrawItem(vcl::RenderContext& rRenderContext, bool bOffScreen
         rRenderContext.SetClipRegion(aRegion);
     }
 
-    // print text
-    Size aTextSize(rRenderContext.GetTextWidth(pItem->maText), rRenderContext.GetTextHeight());
+    SalLayout* pLayoutCache = pItem->mxLayoutCache.get();
+    Size aTextSize(rRenderContext.GetTextWidth(pItem->maText,0,-1,nullptr,&pLayoutCache), rRenderContext.GetTextHeight());
+
+    // update cache if necessary
+    if(pLayoutCache != pItem->mxLayoutCache.get() )
+        pItem->mxLayoutCache.reset(pLayoutCache);
+
     Point aTextPos = ImplGetItemTextPos(aTextRectSize, aTextSize, pItem->mnBits);
+
     if (bOffScreen)
     {
-        mpImplData->mpVirDev->DrawText(aTextPos, pItem->maText);
+        mpImplData->mpVirDev->DrawText(
+                    aTextPos,
+                    pItem->maText,
+                    0, -1, nullptr, nullptr,
+                    &pLayoutCache );
     }
     else
     {
         aTextPos.X() += aTextRect.Left();
         aTextPos.Y() += aTextRect.Top();
-        rRenderContext.DrawText(aTextPos, pItem->maText);
+        rRenderContext.DrawText(
+                    aTextPos,
+                    pItem->maText,
+                    0, -1, nullptr, nullptr,
+                    &pLayoutCache );
     }
 
+    // update cache if necessary
+    if(pLayoutCache != pItem->mxLayoutCache.get() )
+        pItem->mxLayoutCache.reset(pLayoutCache);
+
     // call DrawItem if necessary
     if (pItem->mnBits & StatusBarItemBits::UserDraw)
     {
@@ -830,6 +851,13 @@ void StatusBar::StateChanged( StateChangedType nType )
         ImplInitSettings();
         Invalidate();
     }
+
+    //invalidate layout cache
+    for (ImplStatusItem* pItem : mpItemList)
+    {
+        pItem->mxLayoutCache.reset();
+    }
+
 }
 
 void StatusBar::DataChanged( const DataChangedEvent& rDCEvt )
@@ -852,6 +880,8 @@ void StatusBar::DataChanged( const DataChangedEvent& rDCEvt )
             long nWidth = GetTextWidth( pItem->maText ) + nFudge;
             if( nWidth > pItem->mnWidth + STATUSBAR_OFFSET )
                 pItem->mnWidth = nWidth + STATUSBAR_OFFSET;
+
+            pItem->mxLayoutCache.reset();
         }
         Size aSize = GetSizePixel();
         // do not disturb current width, since
@@ -1133,11 +1163,21 @@ void StatusBar::SetItemText( sal_uInt16 nItemId, const OUString& rText )
 
         if ( pItem->maText != rText )
         {
+            // invalidate cache
+            pItem->mxLayoutCache.reset();
+
             pItem->maText = rText;
 
             // adjust item width - see also DataChanged()
             long nFudge = GetTextHeight()/4;
-            long nWidth = GetTextWidth( pItem->maText ) + nFudge;
+
+            SalLayout* pLayoutCache = nullptr;
+
+            long nWidth = GetTextWidth( pItem->maText,0,-1,nullptr,&pLayoutCache ) + nFudge;
+
+            // update cache
+            pItem->mxLayoutCache.reset(pLayoutCache);
+
             if( (nWidth > pItem->mnWidth + STATUSBAR_OFFSET) ||
                 ((nWidth < pItem->mnWidth) && (mnDX - STATUSBAR_OFFSET) < mnItemsWidth  ))
             {
@@ -1196,6 +1236,8 @@ void StatusBar::SetItemData( sal_uInt16 nItemId, void* pNewData )
     if ( nPos != STATUSBAR_ITEM_NOTFOUND )
     {
         ImplStatusItem* pItem = mpItemList[ nPos ];
+        // invalidate cache
+        pItem->mxLayoutCache.reset();
         pItem->mpUserData = pNewData;
 
         // call Draw-Item if it's a User-Item