Added the DiveProfileItem that uses the DiveProfileModel to diplay data.

I've used the paint() method on it ( even if it's not necessary
on a QGraphicsView ) to reduce absurdely the number of items that are
inserted on the QGraphicsScene ( each small line of the profile should
be an item if it was not for this, it's like that on the old profile. )
and thus reducing the memory consumption, speed and so on.

Signed-off-by: Tomaz Canabrava <tcanabrava@kde.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

qt-ui/profile/diveprofileitem.cpp

@@ -0,0 +1,93 @@
+#include "diveprofileitem.h"
+#include "diveplotdatamodel.h"
+#include "divecartesianaxis.h"
+#include "graphicsview-common.h"
+
+#include <QPen>
+#include <QPainter>
+#include <QLinearGradient>
+
+DiveProfileItem::DiveProfileItem(): QObject(), QGraphicsPolygonItem(),
+	hAxis(NULL), hDataColumn(-1), dataModel(NULL), vAxis(NULL), vDataColumn(-1)
+{
+}
+
+void DiveProfileItem::setHorizontalAxis(DiveCartesianAxis* horizontal)
+{
+	hAxis = horizontal;
+	modelDataChanged();
+}
+
+void DiveProfileItem::setHorizontalDataColumn(int column)
+{
+	hDataColumn = column;
+	modelDataChanged();
+}
+
+void DiveProfileItem::setModel(QAbstractTableModel* model)
+{
+	dataModel = model;
+	modelDataChanged();
+}
+
+void DiveProfileItem::setVerticalAxis(DiveCartesianAxis* vertical)
+{
+	vAxis = vertical;
+	modelDataChanged();
+}
+
+void DiveProfileItem::setVerticalDataColumn(int column)
+{
+	vDataColumn = column;
+	modelDataChanged();
+}
+
+void DiveProfileItem::modelDataChanged()
+{
+	// We don't have enougth data to calculate things, quit.
+	if (!hAxis || !vAxis || !dataModel || hDataColumn == -1 || vDataColumn == -1)
+		return;
+
+	// Calculate the polygon. This is the polygon that will be painted on screen
+	// on the ::paint method. Here we calculate the correct position of the points
+	// regarting our cartesian plane ( made by the hAxis and vAxis ), the QPolygonF
+	// is an array of QPointF's, so we basically get the point from the model, convert
+	// to our coordinates, store. no painting is done here.
+	QPolygonF poly;
+	for(int i = 0, modelDataCount = dataModel->rowCount(); i < modelDataCount; i++){
+		qreal horizontalValue = dataModel->index(i, hDataColumn).data().toReal();
+		qreal verticalValue = dataModel->index(i, vDataColumn).data().toReal();
+		QPointF point( hAxis->posAtValue(horizontalValue), vAxis->posAtValue(verticalValue));
+		poly.append(point);
+	}
+	setPolygon(poly);
+
+	// This is the blueish gradient that the Depth Profile should have.
+	// It's a simple QLinearGradient with 2 stops, starting from top to bottom.
+	QLinearGradient pat(0, poly.boundingRect().top(), 0, poly.boundingRect().bottom());
+	pat.setColorAt(1, getColor(DEPTH_BOTTOM));
+	pat.setColorAt(0, getColor(DEPTH_TOP));
+	setBrush(QBrush(pat));
+}
+
+void DiveProfileItem::paint(QPainter* painter, const QStyleOptionGraphicsItem* option, QWidget* widget){
+	Q_UNUSED(widget);
+
+	// This paints the Polygon + Background. I'm setting the pen to QPen() so we don't get a black line here,
+	// after all we need to plot the correct velocities colors later.
+	setPen(QPen());
+	QGraphicsPolygonItem::paint(painter, option, widget);
+
+	// Here we actually paint the boundaries of the Polygon using the colors that the model provides.
+	// Those are the speed colors of the dives.
+	QPen pen;
+	pen.setCosmetic(true);
+	pen.setWidth(2);
+	// This paints the colors of the velocities.
+	for(int i = 1, count = dataModel->rowCount(); i < count; i++){
+		QModelIndex colorIndex = dataModel->index(i, DivePlotDataModel::COLOR);
+		pen.setBrush(QBrush(colorIndex.data(Qt::BackgroundRole).value<QColor>()));
+		painter->setPen(pen);
+		painter->drawLine(polygon()[i-1],polygon()[i]);
+	}
+}

qt-ui/profile/diveprofileitem.h

@@ -0,0 +1,48 @@
+#ifndef DIVEPROFILEITEM_H
+#define DIVEPROFILEITEM_H
+
+#include <QObject>
+#include <QGraphicsPolygonItem>
+
+/* This is the Profile Item, it should be used for quite a lot of things
+ on the profile view. The usage should be pretty simple:
+
+ DiveProfileItem *profile = new DiveProfileItem();
+ profile->setVerticalAxis( profileYAxis );
+ profile->setHorizontalAxis( timeAxis );
+ profile->setModel( DiveDataModel );
+ profile->setHorizontalDataColumn( DiveDataModel::TIME );
+ profile->setVerticalDataColumn( DiveDataModel::DEPTH );
+ scene()->addItem(profile);
+
+ This is a generically item and should be used as a base for others, I think...
+*/
+
+class DiveCartesianAxis;
+class QAbstractTableModel;
+
+class DiveProfileItem : public QObject, public QGraphicsPolygonItem{
+	Q_OBJECT
+	Q_PROPERTY(QPointF pos WRITE setPos READ pos)
+	Q_PROPERTY(qreal x WRITE setX READ x)
+	Q_PROPERTY(qreal y WRITE setY READ y)
+public:
+	DiveProfileItem();
+	void setVerticalAxis(DiveCartesianAxis *vertical);
+	void setHorizontalAxis(DiveCartesianAxis *horizontal);
+	void setModel(QAbstractTableModel *model);
+	void setHorizontalDataColumn(int column);
+	void setVerticalDataColumn(int column);
+	virtual void paint(QPainter* painter, const QStyleOptionGraphicsItem* option, QWidget* widget = 0);
+public slots:
+	void modelDataChanged();
+private:
+	DiveCartesianAxis *hAxis;
+	DiveCartesianAxis *vAxis;
+	QAbstractTableModel *dataModel;
+	int hDataColumn;
+	int vDataColumn;
+};
+
+
+#endif

subsurface.pro

@@ -70,7 +70,8 @@ HEADERS = \
 	qt-ui/profile/divetextitem.h \
 	qt-ui/profile/animationfunctions.h \
 	qt-ui/profile/divecartesianaxis.h \
-	qt-ui/profile/diveplotdatamodel.h
+	qt-ui/profile/diveplotdatamodel.h \
+	qt-ui/profile/diveprofileitem.h
 
 SOURCES =  \
 	deco.c \
@@ -128,7 +129,8 @@ SOURCES =  \
 	qt-ui/profile/divetextitem.cpp \
 	qt-ui/profile/animationfunctions.cpp \
 	qt-ui/profile/divecartesianaxis.cpp \
-	qt-ui/profile/diveplotdatamodel.cpp
+	qt-ui/profile/diveplotdatamodel.cpp \
+	qt-ui/profile/diveprofileitem.cpp
 
 linux*: SOURCES += linux.c
 mac: SOURCES += macos.c