sc lok: Implement hi-dpi and zoom for spreadsheets.

A bit different approach than trying to paint different zoom levels at
the samet time, because it is terribly hard to achieve with Calc -
things misalign, because Calc tries to fit the lines into the pixels
etc.

Instead, always paint the spreadsheet at 100%, but use cairo to scale the
actual painting.

Change-Id: I228a9dd41bf29862bdd188825d12e61e1c86cccc

2 files changed, 28 insertions, 14 deletions

diff --git a/sc/source/ui/unoobj/docuno.cxx b/sc/source/ui/unoobj/docuno.cxx
index b42179663858..021f316c6236 100644
--- a/sc/source/ui/unoobj/docuno.cxx
+++ b/sc/source/ui/unoobj/docuno.cxx
@@ -978,12 +978,12 @@ bool ScModelObj::isMimeTypeSupported()
     return EditEngine::HasValidData(aDataHelper.GetTransferable());
 }
 
-void ScModelObj::setClientZoom(int nTilePixelWidth_, int nTilePixelHeight_, int nTileTwipWidth_, int nTileTwipHeight_)
+void ScModelObj::setClientZoom(int /*nTilePixelWidth_*/, int /*nTilePixelHeight_*/, int /*nTileTwipWidth_*/, int /*nTileTwipHeight_*/)
 {
-    mnTilePixelWidth = nTilePixelWidth_;
-    mnTilePixelHeight = nTilePixelHeight_;
-    mnTileTwipWidth = nTileTwipWidth_;
-    mnTileTwipHeight = nTileTwipHeight_;
+    mnTilePixelWidth = 256;
+    mnTilePixelHeight = 256;
+    mnTileTwipWidth = mnTilePixelWidth * TWIPS_PER_PIXEL;
+    mnTileTwipHeight = mnTilePixelHeight * TWIPS_PER_PIXEL;
 }
 
 OUString ScModelObj::getRowColumnHeaders(const tools::Rectangle& rRectangle)
diff --git a/sc/source/ui/view/gridwin4.cxx b/sc/source/ui/view/gridwin4.cxx
index 56f19eaf2895..23a01512310d 100644
--- a/sc/source/ui/view/gridwin4.cxx
+++ b/sc/source/ui/view/gridwin4.cxx
@@ -32,6 +32,7 @@
 
 #include <LibreOfficeKit/LibreOfficeKitEnums.h>
 #include <comphelper/lok.hxx>
+#include <comphelper/scopeguard.hxx>
 #include <sfx2/lokhelper.hxx>
 
 #include <svx/svdview.hxx>
@@ -1108,17 +1109,30 @@ void ScGridWindow::PaintTile( VirtualDevice& rDevice,
     // coords only, and avoid all the SetMapMode()'s.
     // Similarly to Writer, we should set the mapmode once on the rDevice, and
     // not care about any zoom settings.
-
-    Fraction aFracX(long(nOutputWidth * TWIPS_PER_PIXEL), nTileWidth);
-    Fraction aFracY(long(nOutputHeight * TWIPS_PER_PIXEL), nTileHeight);
-
-    // page break zoom, and aLogicMode in ScViewData
+    //
+    // But until that happens, we actually draw everything at 100%, and only
+    // set cairo's scale factor accordingly, so that everything is painted
+    // bigger or smaller.  This is different to what Calc's internal scaling
+    // would do - because that one is trying to fit the lines between cells to
+    // integer multiples of pixels.
+    //
+    // See also desktop/source/lib/init.cxx for details, where we have to set
+    // the stuff accorndingly for the VirtualDevice creation.
+
+    // page break zoom, and aLogicMode in ScViewData - hardcode that to what
+    // we mean as 100% (256px tiles meaning 3840 twips)
+    Fraction aFracX(long(256 * TWIPS_PER_PIXEL), 3840);
+    Fraction aFracY(long(256 * TWIPS_PER_PIXEL), 3840);
     pViewData->SetZoom(aFracX, aFracY, true);
 
-    const double fTilePosXPixel = static_cast<double>(nTilePosX) * nOutputWidth / nTileWidth;
-    const double fTilePosYPixel = static_cast<double>(nTilePosY) * nOutputHeight / nTileHeight;
-    const double fTileBottomPixel = static_cast<double>(nTilePosY + nTileHeight) * nOutputHeight / nTileHeight;
-    const double fTileRightPixel = static_cast<double>(nTilePosX + nTileWidth) * nOutputWidth / nTileWidth;
+    // Cairo scales for us, we have to compensate for that, otherwise we are
+    // painting too far away
+    const double fDPIScale = comphelper::LibreOfficeKit::getDPIScale();
+
+    const double fTilePosXPixel = static_cast<double>(nTilePosX) * nOutputWidth / (nTileWidth * fDPIScale);
+    const double fTilePosYPixel = static_cast<double>(nTilePosY) * nOutputHeight / (nTileHeight * fDPIScale);
+    const double fTileBottomPixel = static_cast<double>(nTilePosY + nTileHeight) * nOutputHeight / (nTileHeight * fDPIScale);
+    const double fTileRightPixel = static_cast<double>(nTilePosX + nTileWidth) * nOutputWidth / (nTileWidth * fDPIScale);
 
     SCTAB nTab = pViewData->GetTabNo();
     ScDocument* pDoc = pViewData->GetDocument();