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#include "barchart.h"
#include <algorithm>
#include "geometry.h"
#include "scale.h"
static const QColor OUTLINE_COLOR(0, 0, 0);
static const QColor BAR_COLOR(128, 128, 128);
static const float DEFAULT_OPACITY = 0.8f;
BarChart::BarChart(QQuickItem *parent)
: QQuickItem(parent)
, m_shouldUpdateBars(false)
{
setClip(true);
setFlag(QQuickItem::ItemHasContents);
// setAcceptedMouseButtons(Qt::LeftButton);
setAcceptHoverEvents(true);
}
BarChart::~BarChart()
{
}
void BarChart::setValues(const arma::vec &values)
{
m_values = values;
m_shouldUpdateBars = true;
emit valuesChanged(values);
}
QSGNode *BarChart::newBarNode() const
{
// A bar node is:
// opacityNode [outlineGeomNode barGeomNode]
QSGGeometryNode *outlineGeomNode = new QSGGeometryNode;
QSGGeometry *outlineGeometry =
new QSGGeometry(QSGGeometry::defaultAttributes_Point2D(), 4);
outlineGeometry->setDrawingMode(GL_LINE_LOOP);
outlineGeomNode->setGeometry(outlineGeometry);
outlineGeomNode->setFlag(QSGNode::OwnsGeometry);
QSGFlatColorMaterial *material = new QSGFlatColorMaterial;
material->setColor(OUTLINE_COLOR);
outlineGeomNode->setMaterial(material);
outlineGeomNode->setFlag(QSGNode::OwnsMaterial);
QSGGeometryNode *barGeomNode = new QSGGeometryNode;
QSGGeometry *barGeometry =
new QSGGeometry(QSGGeometry::defaultAttributes_Point2D(), 4);
barGeometry->setDrawingMode(GL_POLYGON);
barGeomNode->setGeometry(barGeometry);
barGeomNode->setFlag(QSGNode::OwnsGeometry);
material = new QSGFlatColorMaterial;
material->setColor(BAR_COLOR);
barGeomNode->setMaterial(material);
barGeomNode->setFlag(QSGNode::OwnsMaterial);
QSGOpacityNode *opacityNode = new QSGOpacityNode;
opacityNode->setOpacity(DEFAULT_OPACITY);
opacityNode->appendChildNode(barGeomNode);
opacityNode->appendChildNode(outlineGeomNode);
return opacityNode;
}
void BarChart::updateBarNodeGeom(QSGNode *barNode, float x, float barWidth, float barHeight)
{
QSGGeometryNode *outlineGeomNode =
static_cast<QSGGeometryNode *>(barNode->firstChild());
QSGGeometryNode *barGeomNode =
static_cast<QSGGeometryNode *>(barNode->firstChild()->nextSibling());
float y = height() - barHeight;
updateRectGeometry(outlineGeomNode->geometry(), x, y, barWidth, barHeight);
updateRectGeometry(barGeomNode->geometry(), x, y, barWidth, barHeight);
}
void BarChart::updateBars(QSGNode *root)
{
QSGNode *node = root->firstChild();
float x = 0;
float barWidth = width() / m_values.n_elem;
LinearScale<float> heightScale(m_values.min(), m_values.max(), 0, height());
for (auto it = m_values.cbegin(); it != m_values.cend(); it++) {
updateBarNodeGeom(node, x, barWidth, heightScale((float) *it));
x += barWidth;
node = node->nextSibling();
}
}
QSGNode *BarChart::updatePaintNode(QSGNode *oldNode, UpdatePaintNodeData *)
{
QSGNode *root = oldNode ? oldNode : new QSGNode;
if (m_shouldUpdateBars) {
int numValues = (int) m_values.n_elem;
// First, make sure we have the same number of values & bars
while (numValues > root->childCount()) {
QSGNode *barNode = newBarNode();
root->appendChildNode(barNode);
}
while (numValues < root->childCount()) {
// NOTE: as stated in docs, QSGNode's children are stored in a
// linked list. Hence, this operation should be as fast as expected
root->removeChildNode(root->firstChild());
}
// Then, update the geometry of bars to reflect the values
updateBars(root);
m_shouldUpdateBars = false;
}
return root;
}
void BarChart::hoverMoveEvent(QHoverEvent *event)
{
// TODO
}
void BarChart::mousePressEvent(QMouseEvent *event)
{
// TODO
}
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