Private API for iterating over QSvgTinyDocument

Expose more node information in the internal API. Also
use the new API to implement a debug operator for
QSvgTinyDocument. Includes a drive-by fix: use floating
point instead of int for rounded rect radius.

Task-number: QTBUG-116883
Change-Id: I238b7313c10b88abd7c2ca755b898ecb6f8c3e8b
Reviewed-by: Eirik Aavitsland <eirik.aavitsland@qt.io>

10 files changed, 397 insertions, 8 deletions

diff --git a/src/svg/CMakeLists.txt b/src/svg/CMakeLists.txt
index bb01c53..0bea57c 100644
--- a/src/svg/CMakeLists.txt
+++ b/src/svg/CMakeLists.txt
@@ -23,6 +23,8 @@ qt_internal_add_module(Svg
         qsvgstructure.cpp qsvgstructure_p.h
         qsvgstyle.cpp qsvgstyle_p.h
         qsvgtinydocument.cpp qsvgtinydocument_p.h
+        qsvgdebug.cpp
+        qsvgvisitor.cpp qsvgvisitor_p.h
         qtsvgglobal.h qtsvgglobal_p.h
     DEFINES
         QT_NO_CONTEXTLESS_CONNECT
diff --git a/src/svg/qsvgdebug.cpp b/src/svg/qsvgdebug.cpp
new file mode 100644
index 0000000..a3cdf8d
--- /dev/null
+++ b/src/svg/qsvgdebug.cpp
@@ -0,0 +1,185 @@
+// Copyright (C) 2023 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+#include "qsvgvisitor_p.h"
+#include <QDebug>
+
+QT_BEGIN_NAMESPACE
+
+static const char *nodeTypeStrings[] = {
+    "DOC",
+    "G",
+    "DEFS",
+    "SWITCH",
+    "ANIMATION",
+    "ARC",
+    "CIRCLE",
+    "ELLIPSE",
+    "IMAGE",
+    "LINE",
+    "PATH",
+    "POLYGON",
+    "POLYLINE",
+    "RECT",
+    "TEXT",
+    "TEXTAREA",
+    "TSPAN",
+    "USE",
+    "VIDEO"
+};
+
+// TODO: something like this is needed in several places. Make a common version.
+static const char *typeName(const QSvgNode *node)
+{
+    constexpr int typeNameCount = sizeof(nodeTypeStrings) / sizeof(const char *);
+    if (node->type() < typeNameCount)
+        return nodeTypeStrings[node->type()];
+    return "UNKNOWN";
+}
+
+class SvgDebugVisitor : public QSvgVisitor
+{
+public:
+    SvgDebugVisitor(QDebug &stream) : debug(stream) {}
+    void write(const QSvgTinyDocument *doc);
+
+protected:
+    void visitNode(const QSvgNode *) override;
+    bool visitStructureNodeStart(const QSvgStructureNode *node) override;
+    void visitStructureNodeEnd(const QSvgStructureNode *) override;
+    void visitAnimationNode(const QSvgAnimation *node) override;
+    void visitEllipseNode(const QSvgEllipse *node) override;
+    void visitImageNode(const QSvgImage *node) override;
+    void visitLineNode(const QSvgLine *node) override;
+    void visitPathNode(const QSvgPath *node) override;
+    void visitPolygonNode(const QSvgPolygon *node) override;
+    void visitPolylineNode(const QSvgPolyline *node) override;
+    void visitRectNode(const QSvgRect *node) override;
+    void visitTextNode(const QSvgText *node) override;
+    void visitUseNode(const QSvgUse *node) override;
+    void visitVideoNode(const QSvgVideo *node) override;
+
+private:
+    const char *indent() { m_indent.fill(' ', m_indentLevel * 2);  return m_indent.constData();}
+    void handleBaseNode(const QSvgNode *node);
+    QDebug &debug;
+    int m_indentLevel = 0;
+    QByteArray m_indent;
+    int nodeCounter = 0;
+};
+
+void SvgDebugVisitor::handleBaseNode(const QSvgNode *node)
+{
+    debug << indent() << typeName(node) << "node, ID:" << node->nodeId();
+    nodeCounter++;
+}
+
+void SvgDebugVisitor::visitNode(const QSvgNode *node)
+{
+    handleBaseNode(node);
+    debug << Qt::endl;
+}
+
+bool SvgDebugVisitor::visitStructureNodeStart(const QSvgStructureNode *node)
+{
+    debug << indent() << "START node" << node->nodeId() << "type" << typeName(node) << node->type() << Qt::endl;
+    m_indentLevel++;
+    return true;
+}
+
+void SvgDebugVisitor::visitStructureNodeEnd(const QSvgStructureNode *node)
+{
+    m_indentLevel--;
+    debug << indent() << "END node" << node->nodeId() << Qt::endl;
+}
+
+void SvgDebugVisitor::visitAnimationNode(const QSvgAnimation *node)
+{
+    handleBaseNode(node);
+    debug << Qt::endl;
+}
+
+void SvgDebugVisitor::visitEllipseNode(const QSvgEllipse *node)
+{
+    handleBaseNode(node);
+    debug << "rect:" << node->rect() << Qt::endl;
+}
+
+void SvgDebugVisitor::visitImageNode(const QSvgImage *node)
+{
+    handleBaseNode(node);
+    debug << "image:" << node->image() << Qt::endl;
+}
+
+void SvgDebugVisitor::visitLineNode(const QSvgLine *node)
+{
+    handleBaseNode(node);
+    debug << "line:" << node->line() << Qt::endl;
+}
+
+void SvgDebugVisitor::visitPathNode(const QSvgPath *node)
+{
+    handleBaseNode(node);
+    debug << "path:" << node->path().elementCount() << "elements." << Qt::endl;
+}
+
+void SvgDebugVisitor::visitPolygonNode(const QSvgPolygon *node)
+{
+    handleBaseNode(node);
+    debug << "polygon:" << node->polygon().size() << "elements." << Qt::endl;
+}
+
+void SvgDebugVisitor::visitPolylineNode(const QSvgPolyline *node)
+{
+    handleBaseNode(node);
+    debug << "polygon:" << node->polygon().size() << "elements." << Qt::endl;
+}
+
+void SvgDebugVisitor::visitRectNode(const QSvgRect *node)
+{
+    handleBaseNode(node);
+    debug << "rect:" << node->rect() << "radius:" << node->radius() << Qt::endl;
+}
+
+void SvgDebugVisitor::visitTextNode(const QSvgText *node)
+{
+    handleBaseNode(node);
+    QString text;
+    for (const auto *tspan : node->tspans()) {
+        if (!tspan)
+            text += QStringLiteral("\\n");
+        else
+            text += tspan->text();
+    }
+    debug << "text:" << text << Qt::endl;
+}
+
+void SvgDebugVisitor::visitUseNode(const QSvgUse *node)
+{
+    handleBaseNode(node);
+    debug << "link ID:" << node->linkId() << Qt::endl;
+}
+
+void SvgDebugVisitor::visitVideoNode(const QSvgVideo *node)
+{
+    handleBaseNode(node);
+    debug << Qt::endl;
+}
+
+void SvgDebugVisitor::write(const QSvgTinyDocument *doc)
+{
+    debug << "SVG" << doc->size() << "viewBox" << doc->viewBox() << Qt::endl;
+    traverse(doc);
+
+    debug << "END SVG" << nodeCounter << "nodes";
+}
+
+QDebug operator<<(QDebug debug, const QSvgTinyDocument &doc)
+{
+    SvgDebugVisitor visitor(debug);
+    visitor.write(&doc);
+
+    return debug;
+}
+
+QT_END_NAMESPACE
diff --git a/src/svg/qsvggraphics.cpp b/src/svg/qsvggraphics.cpp
index 5cb216b..1858d8e 100644
--- a/src/svg/qsvggraphics.cpp
+++ b/src/svg/qsvggraphics.cpp
@@ -250,7 +250,7 @@ void QSvgPolyline::draw(QPainter *p, QSvgExtraStates &states)
     QT_SVG_TIMING_EXIT("Polyline")
 }
 
-QSvgRect::QSvgRect(QSvgNode *node, const QRectF &rect, int rx, int ry)
+QSvgRect::QSvgRect(QSvgNode *node, const QRectF &rect, qreal rx, qreal ry)
     : QSvgNode(node),
       m_rect(rect), m_rx(rx), m_ry(ry)
 {
diff --git a/src/svg/qsvggraphics_p.h b/src/svg/qsvggraphics_p.h
index 9bb005b..42406e3 100644
--- a/src/svg/qsvggraphics_p.h
+++ b/src/svg/qsvggraphics_p.h
@@ -55,6 +55,7 @@ public:
     Type type() const override;
     QRectF fastBounds(QPainter *p, QSvgExtraStates &states) const override;
     QRectF bounds(QPainter *p, QSvgExtraStates &states) const override;
+    QRectF rect() const { return m_bounds; }
 private:
     QRectF m_bounds;
 };
@@ -74,6 +75,9 @@ public:
     void draw(QPainter *p, QSvgExtraStates &states) override;
     Type type() const override;
     QRectF bounds(QPainter *p, QSvgExtraStates &states) const override;
+
+    QRectF rect() const { return m_bounds; }
+    const QImage &image() const { return m_image; }
 private:
     QImage m_image;
     QRectF m_bounds;
@@ -87,6 +91,7 @@ public:
     Type type() const override;
     QRectF fastBounds(QPainter *p, QSvgExtraStates &states) const override;
     QRectF bounds(QPainter *p, QSvgExtraStates &states) const override;
+    QLineF line() const { return m_line; }
 private:
     QLineF m_line;
 };
@@ -100,9 +105,10 @@ public:
     QRectF fastBounds(QPainter *p, QSvgExtraStates &states) const override;
     QRectF bounds(QPainter *p, QSvgExtraStates &states) const override;
 
-    QPainterPath *qpath() {
-        return &m_path;
+    const QPainterPath &path() const {
+        return m_path;
     }
+
 private:
     QPainterPath m_path;
 };
@@ -115,6 +121,9 @@ public:
     Type type() const override;
     QRectF fastBounds(QPainter *p, QSvgExtraStates &states) const override;
     QRectF bounds(QPainter *p, QSvgExtraStates &states) const override;
+    const QPolygonF &polygon() const {
+        return m_poly;
+    }
 private:
     QPolygonF m_poly;
 };
@@ -127,6 +136,9 @@ public:
     Type type() const override;
     QRectF fastBounds(QPainter *p, QSvgExtraStates &states) const override;
     QRectF bounds(QPainter *p, QSvgExtraStates &states) const override;
+    const QPolygonF &polygon() const {
+        return m_poly;
+    }
 private:
     QPolygonF m_poly;
 };
@@ -134,14 +146,16 @@ private:
 class Q_SVG_PRIVATE_EXPORT QSvgRect : public QSvgNode
 {
 public:
-    QSvgRect(QSvgNode *paren, const QRectF &rect, int rx=0, int ry=0);
+    QSvgRect(QSvgNode *paren, const QRectF &rect, qreal rx=0, qreal ry=0);
     Type type() const override;
     void draw(QPainter *p, QSvgExtraStates &states) override;
     QRectF fastBounds(QPainter *p, QSvgExtraStates &states) const override;
     QRectF bounds(QPainter *p, QSvgExtraStates &states) const override;
+    QRectF rect() const { return m_rect; }
+    QPointF radius() const { return { m_rx, m_ry }; }
 private:
     QRectF m_rect;
-    int m_rx, m_ry;
+    qreal m_rx, m_ry;
 };
 
 class  QSvgTspan;
@@ -163,6 +177,7 @@ public:
     Type type() const override;
 
     void addTspan(QSvgTspan *tspan) {m_tspans.append(tspan);}
+    const QList<QSvgTspan *> tspans() const { return m_tspans; }
     void addText(const QString &text);
     void addLineBreak() {m_tspans.append(LINEBREAK);}
     void setWhitespaceMode(WhitespaceMode mode) {m_mode = mode;}
@@ -170,6 +185,9 @@ public:
     QRectF fastBounds(QPainter *p, QSvgExtraStates &states) const override;
     QRectF bounds(QPainter *p, QSvgExtraStates &states) const override;
 
+    QPointF position() const { return m_coord; }
+    QSizeF size() const { return m_size; }
+
 private:
     bool precheck(QPainter *p) const;
     void draw_helper(QPainter *p, QSvgExtraStates &states, QRectF *boundingRect = nullptr) const;
diff --git a/src/svg/qsvghandler.cpp b/src/svg/qsvghandler.cpp
index c870081..08f6e71 100644
--- a/src/svg/qsvghandler.cpp
+++ b/src/svg/qsvghandler.cpp
@@ -3089,9 +3089,7 @@ static QSvgNode *createRectNode(QSvgNode *parent,
     nrx *= (100/(bounds.width()/2));
     nry *= (100/(bounds.height()/2));
 
-    QSvgNode *rect = new QSvgRect(parent, bounds,
-                                  int(nrx),
-                                  int(nry));
+    QSvgNode *rect = new QSvgRect(parent, bounds, nrx, nry);
     return rect;
 }
 
diff --git a/src/svg/qsvgnode_p.h b/src/svg/qsvgnode_p.h
index df1341b..2c23b2f 100644
--- a/src/svg/qsvgnode_p.h
+++ b/src/svg/qsvgnode_p.h
@@ -133,6 +133,7 @@ public:
     void setXmlClass(const QString &str);
 
     bool shouldDrawNode(QPainter *p, QSvgExtraStates &states) const;
+    const QSvgStyle &style() const { return m_style; }
 protected:
     mutable QSvgStyle m_style;
 
diff --git a/src/svg/qsvgstyle_p.h b/src/svg/qsvgstyle_p.h
index 20bd6d5..9581524 100644
--- a/src/svg/qsvgstyle_p.h
+++ b/src/svg/qsvgstyle_p.h
@@ -74,6 +74,8 @@ public:
     inline T *operator->() const { return t; }
     inline operator T*() const { return t; }
 
+    inline bool isDefault() const { return !t || t->isDefault(); }
+
 private:
     T *t;
 };
@@ -138,6 +140,7 @@ public:
     virtual void apply(QPainter *p, const QSvgNode *node, QSvgExtraStates &states) = 0;
     virtual void revert(QPainter *p, QSvgExtraStates &states) =0;
     virtual Type type() const=0;
+    bool isDefault() const { return false; } // [not virtual since called from templated class]
 };
 
 class Q_SVG_PRIVATE_EXPORT QSvgFillStyleProperty : public QSvgStyleProperty
@@ -197,6 +200,9 @@ public:
     void apply(QPainter *p, const QSvgNode *node, QSvgExtraStates &states) override;
     void revert(QPainter *p, QSvgExtraStates &states) override;
     Type type() const override;
+    qreal opacity() const { return m_opacity; }
+    bool isDefault() const { return qFuzzyCompare(m_opacity, 1.0); }
+
 private:
     qreal m_opacity;
     qreal m_oldOpacity;
@@ -597,6 +603,7 @@ public:
     {
         return m_transform;
     }
+    bool isDefault() const { return m_transform.isIdentity(); }
 private:
     //7.6 The transform  attribute
     QTransform m_transform;
diff --git a/src/svg/qsvgtinydocument_p.h b/src/svg/qsvgtinydocument_p.h
index 7f0a9af..539db9c 100644
--- a/src/svg/qsvgtinydocument_p.h
+++ b/src/svg/qsvgtinydocument_p.h
@@ -111,6 +111,8 @@ private:
     const QSvg::FeatureSet m_featureSet;
 };
 
+Q_SVG_PRIVATE_EXPORT QDebug operator<<(QDebug debug, const QSvgTinyDocument &doc);
+
 inline QSize QSvgTinyDocument::size() const
 {
     if (m_size.isEmpty())
diff --git a/src/svg/qsvgvisitor.cpp b/src/svg/qsvgvisitor.cpp
new file mode 100644
index 0000000..fe3ea72
--- /dev/null
+++ b/src/svg/qsvgvisitor.cpp
@@ -0,0 +1,119 @@
+// Copyright (C) 2023 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+#include "qsvgvisitor_p.h"
+
+QT_BEGIN_NAMESPACE
+
+void QSvgVisitor::traverse(const QSvgStructureNode *node)
+{
+    switch (node->type()) {
+    case QSvgNode::SWITCH:
+        if (!visitSwitchNodeStart(static_cast<const QSvgSwitch *>(node)))
+            return;
+        break;
+    case QSvgNode::DOC:
+        if (!visitDocumentNodeStart(static_cast<const QSvgTinyDocument *>(node)))
+            return;
+        break;
+    case QSvgNode::DEFS:
+        if (!visitDefsNodeStart(static_cast<const QSvgDefs *>(node)))
+            return;
+        break;
+    case QSvgNode::G:
+        if (!visitGroupNodeStart(static_cast<const QSvgG *>(node)))
+            return;
+        break;
+    default:
+        Q_UNREACHABLE();
+        break;
+    }
+
+    for (const auto *child : node->renderers()) {
+        switch (child->type()) {
+        case QSvgNode::SWITCH:
+        case QSvgNode::DOC:
+        case QSvgNode::DEFS:
+        case QSvgNode::G:
+            traverse(static_cast<const QSvgStructureNode *>(child));
+            break;
+        case QSvgNode::ANIMATION:
+            visitAnimationNode(static_cast<const QSvgAnimation *>(child));
+            break;
+        case QSvgNode::CIRCLE:
+        case QSvgNode::ELLIPSE:
+            visitEllipseNode(static_cast<const QSvgEllipse *>(child));
+            break;
+        case QSvgNode::IMAGE:
+            visitImageNode(static_cast<const QSvgImage *>(child));
+            break;
+        case QSvgNode::LINE:
+            visitLineNode(static_cast<const QSvgLine *>(child));
+            break;
+        case QSvgNode::PATH:
+            visitPathNode(static_cast<const QSvgPath *>(child));
+            break;
+        case QSvgNode::POLYGON:
+            visitPolygonNode(static_cast<const QSvgPolygon *>(child));
+            break;
+        case QSvgNode::POLYLINE:
+            visitPolylineNode(static_cast<const QSvgPolyline *>(child));
+            break;
+        case QSvgNode::RECT:
+            visitRectNode(static_cast<const QSvgRect *>(child));
+            break;
+        case QSvgNode::TEXT:
+        case QSvgNode::TEXTAREA:
+            visitTextNode(static_cast<const QSvgText *>(child));
+            break;
+        case QSvgNode::TSPAN:
+            visitTspanNode(static_cast<const QSvgTspan *>(child));
+            break;
+        case QSvgNode::USE:
+            visitUseNode(static_cast<const QSvgUse *>(child));
+            break;
+        case QSvgNode::VIDEO:
+            visitVideoNode(static_cast<const QSvgVideo *>(child));
+            break;
+
+        // Enum values that don't have any QSvgNode classes yet:
+           case QSvgNode::MASK:
+           case QSvgNode::SYMBOL:
+           case QSvgNode::MARKER:
+           case QSvgNode::PATTERN:
+           case QSvgNode::FILTER:
+           case QSvgNode::FEMERGE:
+           case QSvgNode::FEMERGENODE:
+           case QSvgNode::FECOLORMATRIX:
+           case QSvgNode::FEGAUSSIANBLUR:
+           case QSvgNode::FEOFFSET:
+           case QSvgNode::FECOMPOSITE:
+           case QSvgNode::FEFLOOD:
+            qDebug() << "Unhandled type in switch" << child->type();
+            break;
+
+           case QSvgNode::ARC: // Not used: to be removed
+            Q_UNREACHABLE();
+            break;
+        }
+    }
+    switch (node->type()) {
+    case QSvgNode::SWITCH:
+        visitSwitchNodeEnd(static_cast<const QSvgSwitch *>(node));
+        break;
+    case QSvgNode::DOC:
+        visitDocumentNodeEnd(static_cast<const QSvgTinyDocument *>(node));
+        break;
+    case QSvgNode::DEFS:
+        visitDefsNodeEnd(static_cast<const QSvgDefs *>(node));
+        break;
+    case QSvgNode::G:
+        visitGroupNodeEnd(static_cast<const QSvgG *>(node));
+        break;
+    default:
+        Q_UNREACHABLE();
+        break;
+    }
+}
+
+QT_END_NAMESPACE
diff --git a/src/svg/qsvgvisitor_p.h b/src/svg/qsvgvisitor_p.h
new file mode 100644
index 0000000..dccff1a
--- /dev/null
+++ b/src/svg/qsvgvisitor_p.h
@@ -0,0 +1,57 @@
+// Copyright (C) 2023 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+#ifndef QSVGVISITOR_P_H
+#define  QSVGVISITOR_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <private/qsvgtinydocument_p.h>
+#include <private/qsvghandler_p.h>
+#include <private/qsvggraphics_p.h>
+#include <private/qsvgstructure_p.h>
+
+QT_BEGIN_NAMESPACE
+
+class Q_SVG_PRIVATE_EXPORT QSvgVisitor {
+public:
+    void traverse(const QSvgStructureNode *node);
+protected:
+    virtual void visitNode(const QSvgNode *) {}
+    virtual bool visitStructureNodeStart(const QSvgStructureNode *node) { visitNode(node); return true; }
+    virtual void visitStructureNodeEnd(const QSvgStructureNode *) {}
+    virtual void visitAnimationNode(const QSvgAnimation *node) { visitNode(node); }
+    virtual void visitEllipseNode(const QSvgEllipse *node) { visitNode(node); }
+    virtual void visitImageNode(const QSvgImage *node) { visitNode(node); }
+    virtual void visitLineNode(const QSvgLine *node) { visitNode(node); }
+    virtual void visitPathNode(const QSvgPath *node) { visitNode(node); }
+    virtual void visitPolygonNode(const QSvgPolygon *node) { visitNode(node); }
+    virtual void visitPolylineNode(const QSvgPolyline *node) { visitNode(node); }
+    virtual void visitRectNode(const QSvgRect *node) { visitNode(node); }
+    virtual void visitTextNode(const QSvgText *node) { visitNode(node); }
+    virtual void visitTspanNode(const QSvgTspan *node) { visitNode(node); }
+    virtual void visitUseNode(const QSvgUse *node) { visitNode(node); }
+    virtual void visitVideoNode(const QSvgVideo *node) { visitNode(node); }
+
+    virtual bool visitDocumentNodeStart(const QSvgTinyDocument *node) { return visitStructureNodeStart(node); }
+    virtual void visitDocumentNodeEnd(const QSvgTinyDocument *node) { visitStructureNodeEnd(node); }
+    virtual bool visitGroupNodeStart(const QSvgG *node) { return visitStructureNodeStart(node); }
+    virtual void visitGroupNodeEnd(const QSvgG *node)  { visitStructureNodeEnd(node); }
+    virtual bool visitDefsNodeStart(const QSvgDefs *node) { return visitStructureNodeStart(node); }
+    virtual void visitDefsNodeEnd(const QSvgDefs *node)  { visitStructureNodeEnd(node); };
+    virtual bool visitSwitchNodeStart(const QSvgSwitch *node) { return visitStructureNodeStart(node); }
+    virtual void visitSwitchNodeEnd(const QSvgSwitch *node)  { visitStructureNodeEnd(node); };
+};
+
+QT_END_NAMESPACE
+
+#endif // QSVGVISITOR_P_H