Merge pull request #1068 from ispyisail/feat/349-image-label

Add a label to pictures (#349)

sources/qetgraphicsitem/diagramimageitem.cpp

@@ -35,6 +35,7 @@
 #include <QBuffer>
 #include <QFileDialog>
 #include <QFileInfo>
+#include <QFontMetricsF>
 #include <QGraphicsSceneContextMenuEvent>
 #include <QImageWriter>
 #include <QMenu>
@@ -69,7 +70,7 @@ DiagramImageItem::DiagramImageItem(const QPixmap &pixmap, QetGraphicsItem *paren
 	// those are a single uniform scale() float, which is exactly why an
 	// image could never break its own aspect ratio before this class
 	// gained proper independent scaleX/scaleY.
-	m_transform.pivot = boundingRect().center();
+	m_transform.pivot = imageRect().center();
 	setTransform(m_transform.toMatrix());
 	setFlags(QGraphicsItem::ItemIsSelectable|QGraphicsItem::ItemIsMovable|QGraphicsItem::ItemSendsGeometryChanges);
 	setAcceptHoverEvents(true);
@@ -110,6 +111,45 @@ void DiagramImageItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *
 		painter -> drawRect(boundingRect());
 		painter -> restore();
 	}
+
+	if (!m_label.isEmpty())
+	{
+		// Undo the picture's own scale so the caption keeps the size of
+		// every other text on the folio whether the picture is shown at
+		// 5 % or 500 %. Rotation and skew are applied after scale in
+		// ShapeTransform::toMatrix(), so the caption still turns with it.
+		const QRectF r = labelRect();
+		painter -> save();
+		painter -> translate(r.topLeft());
+		painter -> scale(1.0 / m_label_scale.x(), 1.0 / m_label_scale.y());
+		painter -> setFont(m_label_font);
+		painter -> setPen(Qt::black);
+		painter -> drawText(QRectF(QPointF(0, 0), m_label_size), Qt::AlignCenter, m_label);
+		painter -> restore();
+	}
+}
+
+/**
+	@brief DiagramImageItem::setLabel
+	Set the caption drawn under the picture. An empty string removes it.
+	@param label
+*/
+void DiagramImageItem::setLabel(const QString &label)
+{
+	if (label == m_label)
+		return;
+
+	prepareGeometryChange();
+	m_label = label;
+	// Font looked up here, not in paint(): diagramTextsFont() reads
+	// QSettings, far too slow to do on every repaint.
+	if (!m_label.isEmpty())
+		m_label_font = QETApp::diagramTextsFont();
+	m_label_size = m_label.isEmpty()
+			? QSizeF()
+			: QFontMetricsF(m_label_font).size(0, m_label);
+	updateLabelScale();
+	emit labelChanged();
 }
 
 /**
@@ -278,7 +318,7 @@ void DiagramImageItem::setPivotRaw(const QPointF &newPivot)
 void DiagramImageItem::resetPivotToBoundingRectCenter()
 {
 	m_pivotIsCustom = false;
-	setPivot(boundingRect().center());
+	setPivot(imageRect().center());
 }
 
 namespace {
@@ -1263,6 +1303,11 @@ QVariant DiagramImageItem::itemChange(GraphicsItemChange change, const QVariant
 		}
 		refreshInteractionHints();
 	}
+	else if (change == ItemTransformChange && !m_label.isEmpty())
+	{
+		prepareGeometryChange();
+		updateLabelScale();
+	}
 	else if (change == ItemPositionHasChanged || change == ItemTransformHasChanged)
 	{
 		if (!m_deferHandleReposition)
@@ -1308,6 +1353,18 @@ QPixmap DiagramImageItem::computeDisplayPixmap(const QPixmap &base, const QRect
 	@return a QRectF represent the bounding rectangle
 */
 QRectF DiagramImageItem::boundingRect() const
+{
+	if (m_label.isEmpty())
+		return imageRect();
+	return imageRect().united(labelRect());
+}
+
+/**
+	@brief DiagramImageItem::imageRect
+	@return the picture's own rectangle, without its label. Handles, the
+	pivot and every other piece of geometry work on this one.
+*/
+QRectF DiagramImageItem::imageRect() const
 {
 	if (!pixmap_.isNull()) {
 		return (QRectF(pixmap_.rect()));
@@ -1317,6 +1374,34 @@ QRectF DiagramImageItem::boundingRect() const
 	}
 }
 
+/**
+	@brief DiagramImageItem::labelRect
+	@return the label's rectangle in item coordinates, centred just under
+	the picture. Divided by the picture's scale, because paint() draws
+	the label unscaled.
+*/
+QRectF DiagramImageItem::labelRect() const
+{
+	const QRectF image = imageRect();
+	const qreal w = m_label_size.width() / m_label_scale.x();
+	const qreal h = m_label_size.height() / m_label_scale.y();
+	const qreal gap = 2.0 / m_label_scale.y();
+	return QRectF(image.center().x() - w / 2.0, image.bottom() + gap, w, h);
+}
+
+/**
+	@brief DiagramImageItem::updateLabelScale
+	The label rect depends on the picture's scale, so boundingRect()
+	changes with it. m_transform is already updated by the time the item
+	transform changes, so the scale is cached here and only refreshed
+	after prepareGeometryChange() has recorded the old rect.
+*/
+void DiagramImageItem::updateLabelScale()
+{
+	const auto safe = [](qreal v) { return qFuzzyIsNull(v) ? 1.0 : qAbs(v); };
+	m_label_scale = QPointF(safe(m_transform.scaleX), safe(m_transform.scaleY));
+}
+
 /**
 	@brief DiagramImageItem::name
 	@return the generic name of this item (picture)
@@ -1474,7 +1559,7 @@ bool DiagramImageItem::fromXml(const QDomElement &e)
 	m_transform.rotation = e.attribute("rotation").toDouble();
 	m_transform.scaleX = e.attribute("size").toDouble();
 	m_transform.scaleY = m_transform.scaleX;
-	m_transform.pivot = boundingRect().center();
+	m_transform.pivot = imageRect().center();
 	m_pivotIsCustom = false;
 
 	const QDomElement transformElement = e.firstChildElement("transform");
@@ -1495,6 +1580,7 @@ bool DiagramImageItem::fromXml(const QDomElement &e)
 	QGraphicsObject::setPos(e.attribute("x").toDouble(), e.attribute("y").toDouble());
 	setZValue(e.attribute("z", QString::number(this->zValue())).toDouble());
 	is_movable_ = (e.attribute("is_movable").toInt());
+	setLabel(e.attribute("label"));
 
 	return (true);
 }
@@ -1525,6 +1611,10 @@ QDomElement DiagramImageItem::toXml(QDomDocument &document) const
 	result.setAttribute("rotation", QString::number(QET::correctAngle(m_transform.rotation)));
 	result.setAttribute("size", QString::number(m_transform.scaleX));
 	result.setAttribute("is_movable", bool(is_movable_));
+	// An attribute, not a child element: fromXml() of every earlier
+	// version requires the base64 text to be the first child.
+	if (!m_label.isEmpty())
+		result.setAttribute("label", m_label);
 
 	//write the pixmap in the xml element after he was been transformed to base64
 	const QByteArray &array = encodedPng(pixmap_, m_png_cache, m_png_cache_key);

sources/qetgraphicsitem/diagramimageitem.h

@@ -23,6 +23,7 @@
 #include "../ui/imagetransparentcolordialog.h"
 
 #include <QColor>
+#include <QFont>
 #include <QList>
 #include <QStyleOptionGraphicsItem>
 #include <QVector>
@@ -46,6 +47,7 @@ class DiagramImageItem : public QetGraphicsItem {
 	Q_PROPERTY(qreal skewX READ skewX WRITE setSkewX NOTIFY transformChanged)
 	Q_PROPERTY(qreal skewY READ skewY WRITE setSkewY NOTIFY transformChanged)
 	Q_PROPERTY(QPointF pivot READ pivot WRITE setPivot NOTIFY transformChanged)
+	Q_PROPERTY(QString label READ label WRITE setLabel NOTIFY labelChanged)
 	// A second, deliberately non-compensating property on the SAME
 	// underlying value -- setPivot() (above) intentionally adjusts
 	// pos() to keep the image visually in place, which is exactly
@@ -123,10 +125,13 @@ class DiagramImageItem : public QetGraphicsItem {
 	QPointF pivot() const { return m_transform.pivot; }
 	void setPivot(const QPointF &pivot);
 	void setPivotRaw(const QPointF &pivot);
+	QString label() const { return m_label; }
+	void setLabel(const QString &label);
 
 	signals:
 	void pixmapChanged();
 	void transformChanged();
+	void labelChanged();
 
 	protected:
 	void paint(QPainter *, const QStyleOptionGraphicsItem *, QWidget *) override;
@@ -176,6 +181,9 @@ class DiagramImageItem : public QetGraphicsItem {
 	static QString hintForHandleRole(HandleRole role);
 	void showStatusHint(const QString &text) const;
 	void clearStatusHint() const;
+	QRectF imageRect() const;
+	QRectF labelRect() const;
+	void updateLabelScale();
 
 	protected:
 	QPixmap pixmap_;
@@ -223,6 +231,13 @@ class DiagramImageItem : public QetGraphicsItem {
 	QPointF m_original_pos;   // scene position at the start of a resize/rotate/pivot drag, for Escape-to-cancel
 	ShapeTransform m_original_transform;
 	bool m_deferHandleReposition = false;   // see setPivot()'s comment
+	// Optional caption drawn centred under the picture (issue #349).
+	// Empty by default, and then neither saved nor painted, so a picture
+	// without one costs exactly what it did before.
+	QString m_label;
+	QFont m_label_font;
+	QSizeF m_label_size;   // in scene units, measured once in setLabel()
+	QPointF m_label_scale{1.0, 1.0};   // scale the label rect was last computed for -- see updateLabelScale()
 	bool m_resizeCenterAnchored = false;   // decided once, at press time -- see handlerMousePressEvent()'s comment for why, mirroring the identical fix already made for shape creation
 };
 #endif

sources/ui/imagepropertieswidget.cpp

@@ -64,16 +64,21 @@ void ImagePropertiesWidget::setImageItem(DiagramImageItem *image)
 	this->setEnabled(true);
 	if (m_image == image) return;
 	if (m_image)
+	{
 		disconnect(m_image, &DiagramImageItem::transformChanged, this, &ImagePropertiesWidget::updateUi);
+		disconnect(m_image, &DiagramImageItem::labelChanged, this, &ImagePropertiesWidget::updateUi);
+	}
 
 	m_image = image;
 	connect(m_image, &DiagramImageItem::transformChanged, this, &ImagePropertiesWidget::updateUi);
+	connect(m_image, &DiagramImageItem::labelChanged, this, &ImagePropertiesWidget::updateUi);
 	m_movable = image->isMovable();
 	m_scaleX = m_image->scaleFactorX();
 	m_scaleY = m_image->scaleFactorY();
 	m_rotation = m_image->rotationAngle();
 	m_skewX = m_image->skewX();
 	m_skewY = m_image->skewY();
+	m_label = m_image->label();
 	updateUi();
 }
 
@@ -101,6 +106,7 @@ void ImagePropertiesWidget::apply()
 	m_rotation = m_image->rotationAngle();
 	m_skewX = m_image->skewX();
 	m_skewY = m_image->skewY();
+	m_label = m_image->label();
 }
 
 /**
@@ -116,6 +122,7 @@ void ImagePropertiesWidget::reset()
 	m_image->setRotationAngle(m_rotation);
 	m_image->setSkewX(m_skewX);
 	m_image->setSkewY(m_skewY);
+	m_image->setLabel(m_label);
 	m_image->setMovable(m_movable);
 	updateUi();
 }
@@ -138,6 +145,7 @@ bool ImagePropertiesWidget::setLiveEdit(bool live_edit)
 		connect (ui->m_angle_sb, &QDoubleSpinBox::editingFinished, this, &ImagePropertiesWidget::apply);
 		connect (ui->m_skew_x_sb, &QDoubleSpinBox::editingFinished, this, &ImagePropertiesWidget::apply);
 		connect (ui->m_skew_y_sb, &QDoubleSpinBox::editingFinished, this, &ImagePropertiesWidget::apply);
+		connect (ui->m_label_le, &QLineEdit::editingFinished, this, &ImagePropertiesWidget::apply);
 	}
 	else
 	{
@@ -146,6 +154,7 @@ bool ImagePropertiesWidget::setLiveEdit(bool live_edit)
 		disconnect (ui->m_angle_sb, &QDoubleSpinBox::editingFinished, this, &ImagePropertiesWidget::apply);
 		disconnect (ui->m_skew_x_sb, &QDoubleSpinBox::editingFinished, this, &ImagePropertiesWidget::apply);
 		disconnect (ui->m_skew_y_sb, &QDoubleSpinBox::editingFinished, this, &ImagePropertiesWidget::apply);
+		disconnect (ui->m_label_le, &QLineEdit::editingFinished, this, &ImagePropertiesWidget::apply);
 	}
 
 	return true;
@@ -191,6 +200,19 @@ QUndoCommand* ImagePropertiesWidget::associatedUndo() const
 	chain("skewX", m_skewX, newSkewX, tr("Modifier l'inclinaison d'une image"));
 	chain("skewY", m_skewY, newSkewY, tr("Modifier l'inclinaison d'une image"));
 
+	// Not through chain(): a string cannot be animated.
+	const QString newLabel = ui->m_label_le->text();
+	if (newLabel != m_label)
+	{
+		if (undo)
+			new QPropertyUndoCommand(m_image, "label", m_label, newLabel, undo);
+		else
+		{
+			undo = new QPropertyUndoCommand(m_image, "label", m_label, newLabel);
+			undo->setText(tr("Modifier le libellé d'une image"));
+		}
+	}
+
 	return undo;
 }
 
@@ -221,6 +243,8 @@ void ImagePropertiesWidget::updateUi()
 	ui->m_skew_x_sb->setValue(m_image->skewX());
 	ui->m_skew_y_sb->setValue(m_image->skewY());
 	ui->m_lock_pos_cb->setChecked(!m_image->isMovable());
+	if (ui->m_label_le->text() != m_image->label())
+		ui->m_label_le->setText(m_image->label());
 }
 
 /**

sources/ui/imagepropertieswidget.h

@@ -70,6 +70,7 @@ class ImagePropertiesWidget : public PropertiesEditorWidget
 		qreal m_rotation;
 		qreal m_skewX;
 		qreal m_skewY;
+		QString m_label;
 		// Guards the width/height spinboxes' mutual updates when
 		// "Conserver les proportions" is checked, so setting one
 		// programmatically in response to the other doesn't re-trigger

sources/ui/imagepropertieswidget.ui

@@ -152,14 +152,28 @@
      </property>
     </widget>
    </item>
-   <item row="6" column="0" colspan="2">
+   <item row="6" column="0">
+    <widget class="QLabel" name="label_label">
+     <property name="text">
+      <string>Libellé</string>
+     </property>
+    </widget>
+   </item>
+   <item row="6" column="1" colspan="2">
+    <widget class="QLineEdit" name="m_label_le">
+     <property name="toolTip">
+      <string>Texte affiché sous l'image. Il suit l'image quand elle est déplacée, copiée ou tournée.</string>
+     </property>
+    </widget>
+   </item>
+   <item row="7" column="0" colspan="2">
     <widget class="QCheckBox" name="m_lock_pos_cb">
      <property name="text">
       <string>Verrouiller la position</string>
      </property>
     </widget>
    </item>
-   <item row="7" column="0">
+   <item row="8" column="0">
     <spacer name="verticalSpacer">
      <property name="orientation">
       <enum>Qt::Vertical</enum>