[PATCH v8 40/44] kernel-shark: Make the label part of the graph

["Yordan Karadzhov (VMware)" <y.karadz@gmail.com>]

The capability to draw text with OpenGL is used. With this
functionality we will no longer need to create special Qt widgets
containing the text of the labels and carefully align those widgets
next to the OpenGL plotting area. This will greatly simplify the
internel structure of the TraceGraph widget.

Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
---
 src/KsPlotTools.cpp | 34 +++++++++++++++++++++++++---------
 src/KsPlotTools.hpp | 18 +++++++++++++++---
 2 files changed, 40 insertions(+), 12 deletions(-)

diff --git a/src/KsPlotTools.cpp b/src/KsPlotTools.cpp
index 4bf08ef..d952f5e 100644
--- a/src/KsPlotTools.cpp
+++ b/src/KsPlotTools.cpp
@@ -759,6 +759,7 @@ Graph::Graph()
   _collectionPtr(nullptr),
   _binColors(nullptr),
   _ensembleColors(nullptr),
+  _label(),
   _zeroSuppress(false)
 {}
 
@@ -777,6 +778,7 @@ Graph::Graph(kshark_trace_histo *histo, KsPlot::ColorTable *bct, KsPlot::ColorTa
   _collectionPtr(nullptr),
   _binColors(bct),
   _ensembleColors(ect),
+  _label(),
   _zeroSuppress(false)
 {
 	if (!_bins) {
@@ -795,10 +797,15 @@ Graph::~Graph()
 	delete[] _bins;
 }
 
+int Graph::_firstBinOffset()
+{
+	return _labelSize + 2 * _hMargin;
+}
+
 void Graph::_initBins()
 {
 	for (int i = 0; i < _size; ++i) {
-		_bins[i]._base.setX(i + _hMargin);
+		_bins[i]._base.setX(i + _firstBinOffset());
 		_bins[i]._base.setY(0);
 		_bins[i]._val.setX(_bins[i]._base.x());
 		_bins[i]._val.setY(_bins[i]._base.y());
@@ -852,6 +859,8 @@ void Graph::setBase(int b)
 	if (b == _bins[0]._base.y()) // Nothing to do.
 		return;
 
+	_label.setBoxAppearance(_label._color, _labelSize, height());
+
 	for (int i = 0; i < _size; ++i) {
 		mod = _bins[i].mod();
 		_bins[i]._base.setY(b);
@@ -870,24 +879,29 @@ void Graph::setHeight(int h)
 }
 
 /**
- * @brief Set the size of the white space added on both sides of the Graph.
+ * @brief Set the color and the dimensions of the graph's label.
  *
- * @param hMargin: the size of the white space in pixels.
+ * @param f: The font to be used to draw the labels.
+ * @param col: The color of the ComboGraph's label.
+ * @param lSize: the size of the graph's label in pixels.
+ * @param hMargin: the size of the white margine space in pixels.
  */
-void Graph::setHMargin(int hMargin)
+void Graph::setLabelAppearance(ksplot_font *f, Color col, int lSize, int hMargin)
 {
 	if (!_size)
 		return;
 
-	if (hMargin == _bins[0]._base.x()) // Nothing to do.
-		return;
+	_labelSize = lSize;
+	_hMargin = hMargin;
+
+	_label.setPos({_hMargin, base()});
+	_label.setFont(f);
+	_label.setBoxAppearance(col, lSize, height());
 
 	for (int i = 0; i < _size; ++i) {
-		_bins[i]._base.setX(i + hMargin);
+		_bins[i]._base.setX(i + _firstBinOffset());
 		_bins[i]._val.setX(_bins[i]._base.x());
 	}
-
-	_hMargin = hMargin;
 }
 
 /**
@@ -1312,6 +1326,8 @@ void Graph::draw(float size)
 	int lastPid(-1), b(0), boxH(_height * .3);
 	Rectangle taskBox;
 
+	_label.draw();
+
 	/*
 	 * Start by drawing a line between the base points of the first and
 	 * the last bin.
diff --git a/src/KsPlotTools.hpp b/src/KsPlotTools.hpp
index 287e0fb..8f530b0 100644
--- a/src/KsPlotTools.hpp
+++ b/src/KsPlotTools.hpp
@@ -506,7 +506,11 @@ public:
 	/** @brief Get a particular bin. */
 	const Bin &bin(int bin) const {return _bins[bin];}
 
-	void setHMargin(int hMargin);
+	/** Set the text of the graph's label. */
+	void setLabelText(std::string text) {_label.setText(text);}
+
+	void setLabelAppearance(ksplot_font *f, Color col,
+				int lSize, int hMargin);
 
 	/**
 	 * Check if this graph is Zero Suppressed. Zero Suppressed means that
@@ -521,7 +525,7 @@ public:
 	 */
 	void setZeroSuppressed(bool zs) {_zeroSuppress = zs;}
 
-private:
+protected:
 	/** Pointer to the model descriptor object. */
 	kshark_trace_histo	*_histoPtr;
 
@@ -537,6 +541,9 @@ private:
 	 */
 	int			_hMargin;
 
+	/** The horizontal size of the Graph's label. */
+	int			_labelSize;
+
 	/** The vertical size (height) of the Graph. */
 	int			_height;
 
@@ -549,9 +556,14 @@ private:
 	/** Hash table of ensemble's colors. */
 	ColorTable		*_ensembleColors;
 
+private:
+	TextBox		_label;
+
 	bool			_zeroSuppress;
 
-	void _initBins();
+	void	_initBins();
+
+	int	_firstBinOffset();
 };
 
 }; // KsPlot
-- 
2.25.1