basegfx: B2DTuple replace operator[] with "get" and Axis2D enum

opertaor[] was used for index access of of x and y variables
where 0 is x and 1 is y - similar like access to an array with 2
elements.

This comes in handy when you write generic code where the
algorithm is the same for x and y, but using index access operator
doesn't look clean and is potentially dangerous. We know we only
have 2 options (o and 1), but an index access allows for more.

A solution to this is to have a normal "get" method, with an enum
as parameter (Axis2D), which can only have values X or Y.

Change-Id: I3f98d0149214808a336f25599350a78436236827
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/90133
Tested-by: Jenkins
Reviewed-by: Tomaž Vajngerl <quikee@gmail.com>

4 files changed, 62 insertions, 33 deletions

diff --git a/chart2/source/view/charttypes/PieChart.cxx b/chart2/source/view/charttypes/PieChart.cxx
index 9694f9cb75cf..94037cdc2272 100644
--- a/chart2/source/view/charttypes/PieChart.cxx
+++ b/chart2/source/view/charttypes/PieChart.cxx
@@ -1330,14 +1330,14 @@ bool PieChart::performLabelBestFitInnerPlacement(ShapeParam& rShapeParam, PieLab
     // compute lengths of the nearest edge and of the orthogonal edges
     double fNearestEdgeLength = fLabelWidth;
     double fOrthogonalEdgeLength = fLabelHeight;
-    int nAxisIndex = 0;
-    int nOrthogonalAxisIndex = 1;
+    basegfx::Axis2D eAxis = basegfx::Axis2D::X;
+    basegfx::Axis2D eOrthogonalAxis = basegfx::Axis2D::Y;
     if( nNearestEdgeIndex % 2 == 0 ) // nearest edge is vertical
     {
         fNearestEdgeLength = fLabelHeight;
         fOrthogonalEdgeLength = fLabelWidth;
-        nAxisIndex = 1;
-        nOrthogonalAxisIndex = 0;
+        eAxis = basegfx::Axis2D::Y;
+        eOrthogonalAxis = basegfx::Axis2D::X;
     }
 
     // compute the distance between N and P
@@ -1454,11 +1454,11 @@ bool PieChart::performLabelBestFitInnerPlacement(ShapeParam& rShapeParam, PieLab
 
     // compute vertices N, M and G respect with pie center C
     basegfx::B2DVector aNearestVertex(aPositionalVector);
-    aNearestVertex[nAxisIndex] += -aDirection[nAxisIndex] * fDistanceNP;
+    aNearestVertex.set(eAxis, aNearestVertex.get(eAxis) - aDirection.get(eAxis) * fDistanceNP);
     basegfx::B2DVector aVertexM(aNearestVertex);
-    aVertexM[nAxisIndex] += aDirection[nAxisIndex] * fNearestEdgeLength;
+    aVertexM.set(eAxis, aVertexM.get(eAxis) + aDirection.get(eAxis) * fNearestEdgeLength);
     basegfx::B2DVector aVertexG(aNearestVertex);
-    aVertexG[nOrthogonalAxisIndex] += aDirection[nOrthogonalAxisIndex] * fOrthogonalEdgeLength;
+    aVertexG.set(eOrthogonalAxis, aVertexG.get(eOrthogonalAxis) + aDirection.get(eOrthogonalAxis) * fOrthogonalEdgeLength);
 
     SAL_INFO( "chart2.pie.label.bestfit.inside",
               "      beta = " << basegfx::rad2deg(fBetaRad) );
@@ -1499,8 +1499,8 @@ bool PieChart::performLabelBestFitInnerPlacement(ShapeParam& rShapeParam, PieLab
         return false;
     }
 
-    if( ( aNearestVertex[nAxisIndex] >= 0 && aVertexM[nAxisIndex] <= 0 )
-            || ( aNearestVertex[nAxisIndex] <= 0 && aVertexM[nAxisIndex] >= 0 ) )
+    if( ( aNearestVertex.get(eAxis) >= 0 && aVertexM.get(eAxis) <= 0 )
+            || ( aNearestVertex.get(eAxis) <= 0 && aVertexM.get(eAxis) >= 0 ) )
     {
         // check the angle between CP and CN
         fAngleRad = aPositionalVector.angle(aNearestVertex);
@@ -1531,13 +1531,13 @@ bool PieChart::performLabelBestFitInnerPlacement(ShapeParam& rShapeParam, PieLab
 
     // compute the b.b. center respect with the pie center
     basegfx::B2DVector aBBCenter(aNearestVertex);
-    aBBCenter[nAxisIndex] += aDirection[nAxisIndex] * fNearestEdgeLength / 2;
-    aBBCenter[nOrthogonalAxisIndex] += aDirection[nOrthogonalAxisIndex] * fOrthogonalEdgeLength / 2;
+    aBBCenter.set(eAxis, aBBCenter.get(eAxis) + aDirection.get(eAxis) * fNearestEdgeLength / 2);
+    aBBCenter.set(eOrthogonalAxis, aBBCenter.get(eOrthogonalAxis) + aDirection.get(eOrthogonalAxis) * fOrthogonalEdgeLength / 2);
 
     // compute the b.b. anchor point
     basegfx::B2IVector aNewAnchorPoint = aPieCenter;
-    aNewAnchorPoint[0] += floor(aBBCenter[0]);
-    aNewAnchorPoint[1] -= floor(aBBCenter[1]); // the Y axis on the screen points downward
+    aNewAnchorPoint.setX(aNewAnchorPoint.getX() + floor(aBBCenter.getX()));
+    aNewAnchorPoint.setY(aNewAnchorPoint.getY() - floor(aBBCenter.getY())); // the Y axis on the screen points downward
 
     // compute the translation vector for moving the label from the current
     // screen position to the new one
diff --git a/include/basegfx/tuple/b2dtuple.hxx b/include/basegfx/tuple/b2dtuple.hxx
index 059820bd78fd..d26310de9975 100644
--- a/include/basegfx/tuple/b2dtuple.hxx
+++ b/include/basegfx/tuple/b2dtuple.hxx
@@ -23,6 +23,7 @@
 #include <sal/types.h>
 #include <basegfx/numeric/ftools.hxx>
 #include <basegfx/basegfxdllapi.h>
+#include <basegfx/utils/common.hxx>
 
 namespace basegfx
 {
@@ -39,10 +40,11 @@ namespace basegfx
     class SAL_WARN_UNUSED B2DTuple
     {
     protected:
-        double                                      mfX;
-        double                                      mfY;
+        double mfX;
+        double mfY;
 
     public:
+
         /** Create a 2D Tuple
 
             The tuple is initialized to (0.0, 0.0)
@@ -98,27 +100,21 @@ namespace basegfx
             mfY = fY;
         }
 
-        /// Array-access to 2D Tuple
-        const double& operator[] (int nPos) const
+        double get(Axis2D eAxis)
         {
-            // Here, normally one if(...) should be used. In the assumption that
-            // both double members can be accessed as an array a shortcut is used here.
-            // if(0 == nPos) return mfX; return mfY;
-            return *((&mfX) + nPos);
+            return eAxis == Axis2D::X ? getX() : getY();
         }
 
-        /// Array-access to 2D Tuple
-        double& operator[] (int nPos)
+        void set(Axis2D eAxis, double fValue)
         {
-            // Here, normally one if(...) should be used. In the assumption that
-            // both double members can be accessed as an array a shortcut is used here.
-            // if(0 == nPos) return mfX; return mfY;
-            return *((&mfX) + nPos);
+            if (eAxis == Axis2D::X)
+                setX(fValue);
+            else
+                setY(fValue);
         }
 
         // comparators with tolerance
 
-
         bool equalZero() const
         {
             return (this == &getEmptyTuple() ||
diff --git a/include/basegfx/utils/common.hxx b/include/basegfx/utils/common.hxx
new file mode 100644
index 000000000000..522bfbcb2bff
--- /dev/null
+++ b/include/basegfx/utils/common.hxx
@@ -0,0 +1,33 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ *   Licensed to the Apache Software Foundation (ASF) under one or more
+ *   contributor license agreements. See the NOTICE file distributed
+ *   with this work for additional information regarding copyright
+ *   ownership. The ASF licenses this file to you under the Apache
+ *   License, Version 2.0 (the "License"); you may not use this file
+ *   except in compliance with the License. You may obtain a copy of
+ *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
+ */
+
+#pragma once
+
+namespace basegfx
+{
+// The axis or dimension in a 2D coordiante system
+enum class Axis2D
+{
+    X,
+    Y
+};
+
+} // end of namespace basegfx
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/svx/source/table/tablehandles.cxx b/svx/source/table/tablehandles.cxx
index daaf45c8832c..2760755421c1 100644
--- a/svx/source/table/tablehandles.cxx
+++ b/svx/source/table/tablehandles.cxx
@@ -116,17 +116,17 @@ void TableEdgeHdl::getPolyPolygon(basegfx::B2DPolyPolygon& rVisible, basegfx::B2
 
     if( pDrag )
     {
-        int n = mbHorizontal ? 1 : 0;
-        aOffset[n] = aOffset[n] + GetValidDragOffset( *pDrag );
+        basegfx::Axis2D eDragAxis = mbHorizontal ? basegfx::Axis2D::Y : basegfx::Axis2D::X;
+        aOffset.set(eDragAxis, aOffset.get(eDragAxis) + GetValidDragOffset( *pDrag ));
     }
 
     basegfx::B2DPoint aStart(aOffset), aEnd(aOffset);
-    int nPos = mbHorizontal ? 0 : 1;
+    basegfx::Axis2D eAxis = mbHorizontal ? basegfx::Axis2D::X : basegfx::Axis2D::Y;
 
     for( const TableEdge& aEdge : maEdges )
     {
-        aStart[nPos] = aOffset[nPos] + aEdge.mnStart;
-        aEnd[nPos] = aOffset[nPos] + aEdge.mnEnd;
+        aStart.set(eAxis, aOffset.get(eAxis) + aEdge.mnStart);
+        aEnd.set(eAxis, aOffset.get(eAxis) + aEdge.mnEnd);
 
         basegfx::B2DPolygon aPolygon;
         aPolygon.append( aStart );