editeng: use text scaling that better mimics MSO text scaling

Implement text scaling algorithm that is similar to MSO text
scaling for text boxes for the compatibility purpuse, so that the
Impress slides better match how the PP slides are layed out.

This also moves the implementation into EditEng, where it is
possible to better control how searching for the best scaling
factor is performed without doing additional irrelevant work or
trigger invalidations that should not be triggered.

An additional change is that the paragraph with no content at the
end are ignored, and are not taken into account when determining
the height of the content. This is done for compatibility reasons.

Fix horizontal spacing of tabs - the spacing shouldn't be scaled
and the tab shouldn't include the space at the beginning of the
line.

Change-Id: Ie37fa67f1cf300e915a4ebaef2a7f968bf6c5744
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/165441
Tested-by: Jenkins
Reviewed-by: Tomaž Vajngerl <quikee@gmail.com>

3 files changed, 25 insertions, 114 deletions

diff --git a/svx/source/svdraw/svdotext.cxx b/svx/source/svdraw/svdotext.cxx
index 8e5e1f835542..526b4d8b0b8e 100644
--- a/svx/source/svdraw/svdotext.cxx
+++ b/svx/source/svdraw/svdotext.cxx
@@ -1233,14 +1233,14 @@ void SdrTextObj::ImpSetupDrawOutlinerForPaint( bool             bContourFrame,
     }
     else if (IsAutoFit())
     {
-        ImpAutoFitText(rOutliner);
+        setupAutoFitText(rOutliner);
     }
 }
 
 double SdrTextObj::GetFontScale() const
 {
     SdrOutliner& rOutliner = ImpGetDrawOutliner();
-    // This eventually calls ImpAutoFitText
+    // This eventually calls setupAutoFitText
     UpdateOutlinerFormatting(rOutliner, o3tl::temporary(tools::Rectangle()));
 
     return rOutliner.getScalingParameters().fFontY;
@@ -1249,133 +1249,41 @@ double SdrTextObj::GetFontScale() const
 double SdrTextObj::GetSpacingScale() const
 {
     SdrOutliner& rOutliner = ImpGetDrawOutliner();
-    // This eventually calls ImpAutoFitText
+    // This eventually calls setupAutoFitText
     UpdateOutlinerFormatting(rOutliner, o3tl::temporary(tools::Rectangle()));
 
     return rOutliner.getScalingParameters().fSpacingY;
 }
 
-void SdrTextObj::ImpAutoFitText( SdrOutliner& rOutliner ) const
+void SdrTextObj::setupAutoFitText(SdrOutliner& rOutliner) const
 {
-    const Size aShapeSize=GetSnapRect().GetSize();
-    ImpAutoFitText( rOutliner,
-                    Size(aShapeSize.Width()-GetTextLeftDistance()-GetTextRightDistance(),
-                         aShapeSize.Height()-GetTextUpperDistance()-GetTextLowerDistance()),
-                    IsVerticalWriting() );
-}
+    const Size aShapeSize = GetSnapRect().GetSize();
+    Size aSize(aShapeSize.Width() - GetTextLeftDistance() - GetTextRightDistance(),
+               aShapeSize.Height() - GetTextUpperDistance() - GetTextLowerDistance());
 
-void SdrTextObj::ImpAutoFitText(SdrOutliner& rOutliner, const Size& rTextSize,
-                                bool bIsVerticalWriting) const
-{
-    autoFitTextForCompatibility(rOutliner, rTextSize, bIsVerticalWriting);
+    setupAutoFitText(rOutliner, aSize);
 }
-
-void SdrTextObj::autoFitTextForCompatibility(SdrOutliner& rOutliner, const Size& rTextBoxSize, bool bIsVerticalWriting) const
+void SdrTextObj::setupAutoFitText(SdrOutliner& rOutliner, const Size& rTextBoxSize) const
 {
-    rOutliner.setRoundFontSizeToPt(true);
+    rOutliner.setRoundFontSizeToPt(true); // We need to round the font size nearest integer pt size
+    rOutliner.SetMaxAutoPaperSize(rTextBoxSize);
+    rOutliner.SetPaperSize(rTextBoxSize);
 
     const SdrTextFitToSizeTypeItem& rItem = GetObjectItem(SDRATTR_TEXT_FITTOSIZE);
-    double fMaxScale = rItem.getFontScale();
-    if (fMaxScale > 0.0)
-    {
-        rOutliner.setScalingParameters({ fMaxScale, fMaxScale, 100.0, 100.0 });
-    }
-    else
-    {
-        fMaxScale = 100.0;
-    }
-
-    Size aCurrentTextBoxSize = rOutliner.CalcTextSizeNTP();
-    if (aCurrentTextBoxSize.Height() == 0)
-        return;
 
-    tools::Long nExtendTextBoxBy = -50;
-    aCurrentTextBoxSize.extendBy(0, nExtendTextBoxBy);
-    double fCurrentFitFactor = 1.0;
+    double fFontScale = rItem.getFontScale();
+    double fSpacingScale = rItem.getSpacingScale();
 
-    if (bIsVerticalWriting)
-        fCurrentFitFactor = double(rTextBoxSize.Width()) / aCurrentTextBoxSize.Width();
-    else
-        fCurrentFitFactor = double(rTextBoxSize.Height()) / aCurrentTextBoxSize.Height();
-
-    auto aParameters = rOutliner.getScalingParameters();
-    double fInitialFontScaleY = aParameters.fFontY;
-    double fInitialSpacing = aParameters.fSpacingY;
-
-    if (fCurrentFitFactor >= 1.0 && fInitialFontScaleY >= 100.0 && fInitialSpacing >= 100.0)
-        return;
-
-    sal_Int32 nFontHeight = GetObjectItemSet().Get(EE_CHAR_FONTHEIGHT).GetHeight();
-
-    double fFontHeightPt = o3tl::convert(double(nFontHeight), o3tl::Length::mm100, o3tl::Length::pt);
-    double fMinY = 0.0;
-    double fMaxY = fMaxScale;
-
-    double fBestFontScale = 0.0;
-    double fBestSpacing = 100.0;
-    double fBestFitFactor = fCurrentFitFactor;
-
-    if (fCurrentFitFactor >= 1.0)
+    if (fFontScale > 0.0 && fSpacingScale > 0.0 && !mbInEditMode)
     {
-        fMinY = fInitialFontScaleY;
-        fBestFontScale = fInitialFontScaleY;
-        fBestSpacing = fInitialSpacing;
-        fBestFitFactor = fCurrentFitFactor;
+        rOutliner.setScalingParameters({ fFontScale, fFontScale, 100.0, fSpacingScale });
     }
     else
     {
-        fMaxY = std::min(fInitialFontScaleY, fMaxScale);
+        rOutliner.resetScalingParameters();
     }
 
-    double fInTheMidle = 0.5;
-
-    int iteration = 0;
-    double fFitFactorTarget = 1.00;
-
-    while (iteration < 10)
-    {
-        iteration++;
-        double fScaleY = fMinY + (fMaxY - fMinY) * fInTheMidle;
-
-        double fScaledFontHeight = fFontHeightPt * (fScaleY / 100.0);
-        double fRoundedScaledFontHeight = std::floor(fScaledFontHeight * 10.0) / 10.0;
-        double fCurrentFontScale = (fRoundedScaledFontHeight / fFontHeightPt) * 100.0;
-
-        fCurrentFitFactor = 0.0; // reset fit factor;
-
-        for (double fCurrentSpacing : {100.0, 90.0, 80.0})
-        {
-            if (fCurrentFitFactor >= fFitFactorTarget)
-                continue;
-
-            rOutliner.setScalingParameters({ fCurrentFontScale, fCurrentFontScale, 100.0, fCurrentSpacing });
-
-            aCurrentTextBoxSize = rOutliner.CalcTextSizeNTP();
-            aCurrentTextBoxSize.extendBy(0, nExtendTextBoxBy);
-            if (bIsVerticalWriting)
-                fCurrentFitFactor = double(rTextBoxSize.Width()) / aCurrentTextBoxSize.Width();
-            else
-                fCurrentFitFactor = double(rTextBoxSize.Height()) / aCurrentTextBoxSize.Height();
-
-
-            if (fCurrentSpacing == 100.0)
-            {
-                if (fCurrentFitFactor > fFitFactorTarget)
-                    fMinY = fCurrentFontScale;
-                else
-                    fMaxY = fCurrentFontScale;
-            }
-
-            if ((fBestFitFactor < fFitFactorTarget && fCurrentFitFactor > fBestFitFactor)
-            ||  (fCurrentFitFactor >= fFitFactorTarget && fCurrentFitFactor < fBestFitFactor))
-            {
-                fBestFontScale = fCurrentFontScale;
-                fBestSpacing = fCurrentSpacing;
-                fBestFitFactor = fCurrentFitFactor;
-            }
-        }
-    }
-    rOutliner.setScalingParameters({ fBestFontScale, fBestFontScale, 100.0, fBestSpacing });
+    rOutliner.QuickFormatDoc();
 }
 
 void SdrTextObj::SetupOutlinerFormatting( SdrOutliner& rOutl, tools::Rectangle& rPaintRect ) const
@@ -1966,10 +1874,13 @@ void SdrTextObj::onEditOutlinerStatusEvent( EditStatus* pEditStatus )
         assert(mpEditingOutliner);
         mbInDownScale = true;
 
+        // Need to reset scaling so it searches for the fitting size again
+        mpEditingOutliner->resetScalingParameters();
+
         // sucks that we cannot disable paints via
         // mpEditingOutliner->SetUpdateMode(FALSE) - but EditEngine skips
         // formatting as well, then.
-        ImpAutoFitText(*mpEditingOutliner);
+        setupAutoFitText(*mpEditingOutliner);
         mbInDownScale = false;
     }
 }
diff --git a/svx/source/svdraw/svdotextdecomposition.cxx b/svx/source/svdraw/svdotextdecomposition.cxx
index e54fdfd76cd7..7b94bfbc1093 100644
--- a/svx/source/svdraw/svdotextdecomposition.cxx
+++ b/svx/source/svdraw/svdotextdecomposition.cxx
@@ -935,11 +935,11 @@ void SdrTextObj::impDecomposeAutoFitTextPrimitive(
         rOutliner.SetMinColumnWrapHeight(nAnchorTextWidth);
     }
 
-    rOutliner.SetPaperSize(aNullSize);
+    rOutliner.SetPaperSize(aAnchorTextSize);
     rOutliner.SetUpdateLayout(true);
     rOutliner.SetText(*pOutlinerParaObject);
-    ImpAutoFitText(rOutliner,aAnchorTextSize,bVerticalWriting);
 
+    setupAutoFitText(rOutliner, aAnchorTextSize);
     // set visualizing page at Outliner; needed e.g. for PageNumberField decomposition
     rOutliner.setVisualizedPage(GetSdrPageFromXDrawPage(aViewInformation.getVisualizedPage()));
 
diff --git a/svx/source/svdraw/svdotxed.cxx b/svx/source/svdraw/svdotxed.cxx
index 120bf26b1751..8666f262be92 100644
--- a/svx/source/svdraw/svdotxed.cxx
+++ b/svx/source/svdraw/svdotxed.cxx
@@ -110,7 +110,7 @@ bool SdrTextObj::BegTextEdit(SdrOutliner& rOutl)
     }
     else if (IsAutoFit())
     {
-        ImpAutoFitText(rOutl);
+        setupAutoFitText(rOutl);
     }
 
     if(pOutlinerParaObject)