Improve color highlighting of memory view.

Factor out and streamline code from the annotation highlighter
to create a list of colors suitable for highlighting and use that
in memory view.

Task-number: QTCREATORBUG-8250
Change-Id: Iefd408847897ddc98e3aecd6e4f084d1415b80c0
Reviewed-by: hjk <qthjk@ovi.com>

src/plugins/debugger/watchwindow.cpp

@@ -43,6 +43,8 @@
 #include "debuggertooltipmanager.h"
 #include "memoryagent.h"
 
+#include <texteditor/syntaxhighlighter.h>
+
 #include <utils/qtcassert.h>
 #include <utils/savedaction.h>
 
@@ -331,30 +333,18 @@ static MemoryMarkupList
             }
     }
 
-    // Condense ranges of identical color into markup ranges. Assign member colors
-    // interchangeably.
-    const QColor baseColor = sizeIsEstimate ? defaultBackground : Qt::lightGray;
+    // Assign colors from a list, use base color for 0 (contrast to black text).
+    QList<QColor> colors = TextEditor::SyntaxHighlighter::generateColors(colorNumber + 1,
+                                                                         QColor(Qt::black));
+    colors.prepend(sizeIsEstimate ? defaultBackground : Qt::lightGray);
     const QColor registerColor = Qt::green;
-    QColor memberColor1 = QColor(Qt::yellow).lighter();
-    QColor memberColor2 = QColor(Qt::cyan).lighter();
-
     int lastColorNumber = 0;
-    int childNumber = 0;
     for (unsigned i = 0; i < size; ++i) {
         const ColorNumberToolTip &range = ranges.at(i);
         if (result.isEmpty() || lastColorNumber != range.first) {
             lastColorNumber = range.first;
-            // Base colors: Parent/register
-            QColor color = range.first == registerColorNumber ? registerColor : baseColor;
-            if (range.first && range.first != registerColorNumber) {
-                if (childNumber++ & 1) { // Alternating member colors.
-                    color = memberColor1;
-                    memberColor1 = memberColor1.darker(120);
-                } else {
-                    color = memberColor2;
-                    memberColor2 = memberColor2.darker(120);
-                }
-            } // color switch
+            const QColor color = range.first == registerColorNumber ?
+                         registerColor : colors.at(range.first);
             result.push_back(MemoryMarkup(address + i, 1, color, range.second));
         } else {
             result.back().length++;

src/plugins/texteditor/syntaxhighlighter.cpp

@@ -40,6 +40,8 @@
 #include <qtextedit.h>
 #include <qtimer.h>
 
+#include <math.h>
+
 using namespace TextEditor;
 
 class TextEditor::SyntaxHighlighterPrivate
@@ -755,4 +757,38 @@ void SyntaxHighlighter::setExtraAdditionalFormats(const QTextBlock& block,
     d->inReformatBlocks = wasInReformatBlocks;
 }
 
+/* Generate at least n different colors for highlighting, excluding background
+ * color. */
+
+QList<QColor> SyntaxHighlighter::generateColors(int n, const QColor &background)
+{
+    QList<QColor> result;
+    // Assign a color gradient. Generate a sufficient number of colors
+    // by using ceil and looping from 0..step.
+    const double oneThird = 1.0 / 3.0;
+    const int step = qRound(ceil(pow(double(n), oneThird)));
+    result.reserve(step * step * step);
+    const int factor = 255 / step;
+    const int half = factor / 2;
+    const int bgRed = background.red();
+    const int bgGreen = background.green();
+    const int bgBlue = background.blue();
+    for (int r = step; r >= 0; --r) {
+        const int red = r * factor;
+        if (bgRed - half > red || bgRed + half <= red) {
+            for (int g = step; g >= 0; --g) {
+                const int green = g * factor;
+                if (bgGreen - half > green || bgGreen + half <= green) {
+                    for (int b = step; b >= 0 ; --b) {
+                        const int blue = b * factor;
+                        if (bgBlue - half > blue || bgBlue + half <= blue)
+                            result.append(QColor(red, green, blue));
+                    }
+                }
+            }
+        }
+    }
+    return result;
+}
+
 #include "moc_syntaxhighlighter.cpp"

src/plugins/texteditor/syntaxhighlighter.h

@@ -66,6 +66,8 @@ public:
 
     void setExtraAdditionalFormats(const QTextBlock& block, const QList<QTextLayout::FormatRange> &formats);
 
+    static QList<QColor> generateColors(int n, const QColor &background);
+
 public Q_SLOTS:
     void rehighlight();
     void rehighlightBlock(const QTextBlock &block);

src/plugins/vcsbase/baseannotationhighlighter.cpp

@@ -29,7 +29,6 @@
 
 #include "baseannotationhighlighter.h"
 
-#include <math.h>
 #include <QSet>
 #include <QDebug>
 #include <QColor>
@@ -81,26 +80,12 @@ BaseAnnotationHighlighter::~BaseAnnotationHighlighter()
 
 void BaseAnnotationHighlighter::setChangeNumbers(const ChangeNumbers &changeNumbers)
 {
-    QColor bg = d->m_background;
     d->m_changeNumberMap.clear();
     if (!changeNumbers.isEmpty()) {
         // Assign a color gradient to annotation change numbers. Give
         // each change number a unique color.
-        const double oneThird = 1.0 / 3.0;
-        const int step = qRound(ceil(pow(double(changeNumbers.count()), oneThird)));
-        QList<QColor> colors;
-        const int factor = 255 / step;
-        int half = factor / 2;
-        for (int i=0; i<=step; ++i)
-            for (int j=0; j<=step; ++j)
-                for (int k=0; k<=step; ++k) {
-                    QColor c(i*factor, j*factor, k*factor);
-                    if ((bg.red() - half > c.red() ||bg.red() + half <= c.red())
-                            && (bg.green() - half > c.green() || bg.green() + half <= c.green())
-                            && (bg.blue() - half > c.blue() || bg.blue() + half <= c.blue()))
-                        colors.prepend(c);
-                }
-
+        const QList<QColor> colors =
+            TextEditor::SyntaxHighlighter::generateColors(changeNumbers.size(), d->m_background);
         int m = 0;
         const int cstep = colors.count() / changeNumbers.count();
         const ChangeNumbers::const_iterator cend = changeNumbers.constEnd();