Doc: compile plaintextlayout snippet

Done-with: Nico Vertriest <nico.vertriest@qt.io>
Task-number: QTBUG-81486
Change-Id: I2bac37fd41703cc4cfb7de3946b31412c4af37b9
Reviewed-by: Topi Reiniö <topi.reinio@qt.io>

src/gui/doc/snippets/plaintextlayout/plaintextlayout.pro

@@ -1,3 +1,6 @@
-HEADERS     = window.h
-SOURCES     = main.cpp \
-              window.cpp
+TEMPLATE = lib
+TARGET = plaintextlayout_snippets
+QT += core gui widgets
+
+SOURCES = \
+    window.cpp

src/gui/doc/snippets/plaintextlayout/window.cpp

@@ -47,72 +47,67 @@
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
+#include <QPainter>
+#include <QTextLayout>
+#include <QWidget>
 
-#include <QtGui>
-#include <math.h>
-
-#include "window.h"
-
-Window::Window(QWidget *parent)
-    : QWidget(parent)
+namespace plaintextlayout {
+class Window : public QWidget
 {
-    text = QString("Support for text rendering and layout in Qt 4 has been "
-                   "redesigned around a system that allows textual content to "
-                   "be represented in a more flexible way than was possible "
-                   "with Qt 3. Qt 4 also provides a more convenient "
-                   "programming interface for editing documents. These "
-                   "improvements are made available through a reimplementation "
-                   "of the existing text rendering engine, and the "
-                   "introduction of several new classes. "
-                   "See the relevant module overview for a detailed discussion "
-                   "of this framework. The following sections provide a brief "
-                   "overview of the main concepts behind Scribe.");
+protected:
+    void paintEvent(QPaintEvent *event) override;
 
-    setWindowTitle(tr("Plain Text Layout"));
-}
+private:
+    QFont font;
+    QString text;
+};
 
 void Window::paintEvent(QPaintEvent *event)
 {
+
 //! [0]
-    QTextLayout textLayout(text, font);
-    qreal margin = 10;
-    qreal radius = qMin(width()/2.0, height()/2.0) - margin;
-    QFontMetrics fm(font);
+QTextLayout textLayout(text, font);
+qreal margin = 10;
+qreal radius = qMin(width()/2.0, height()/2.0) - margin;
+QFontMetrics fm(font);
 
-    qreal lineHeight = fm.height();
-    qreal y = 0;
+qreal lineHeight = fm.height();
+qreal y = 0;
 
-    textLayout.beginLayout();
+textLayout.beginLayout();
 
-    while (1) {
-        // create a new line
-        QTextLine line = textLayout.createLine();
-        if (!line.isValid())
-            break;
+while (1) {
+    // create a new line
+    QTextLine line = textLayout.createLine();
+    if (!line.isValid())
+        break;
 
-        qreal x1 = qMax(0.0, pow(pow(radius,2)-pow(radius-y,2), 0.5));
-        qreal x2 = qMax(0.0, pow(pow(radius,2)-pow(radius-(y+lineHeight),2), 0.5));
-        qreal x = qMax(x1, x2) + margin;
-        qreal lineWidth = (width() - margin) - x;
+    qreal x1 = qMax(0.0, pow(pow(radius,2)-pow(radius-y,2), 0.5));
+    qreal x2 = qMax(0.0, pow(pow(radius,2)-pow(radius-(y+lineHeight),2), 0.5));
+    qreal x = qMax(x1, x2) + margin;
+    qreal lineWidth = (width() - margin) - x;
 
-        line.setLineWidth(lineWidth);
-        line.setPosition(QPointF(x, margin+y));
-        y += line.height();
-    }
-
-    textLayout.endLayout();
-
-    QPainter painter;
-    painter.begin(this);
-    painter.setRenderHint(QPainter::Antialiasing);
-    painter.fillRect(rect(), Qt::white);
-    painter.setBrush(QBrush(Qt::black));
-    painter.setPen(QPen(Qt::black));
-    textLayout.draw(&painter, QPoint(0,0));
-
-    painter.setBrush(QBrush(QColor("#a6ce39")));
-    painter.setPen(QPen(Qt::black));
-    painter.drawEllipse(QRectF(-radius, margin, 2*radius, 2*radius));
-    painter.end();
-//! [0]
+    line.setLineWidth(lineWidth);
+    line.setPosition(QPointF(x, margin+y));
+    y += line.height();
 }
+
+textLayout.endLayout();
+
+QPainter painter;
+painter.begin(this);
+painter.setRenderHint(QPainter::Antialiasing);
+painter.fillRect(rect(), Qt::white);
+painter.setBrush(QBrush(Qt::black));
+painter.setPen(QPen(Qt::black));
+textLayout.draw(&painter, QPoint(0,0));
+
+painter.setBrush(QBrush(QColor("#a6ce39")));
+painter.setPen(QPen(Qt::black));
+painter.drawEllipse(QRectF(-radius, margin, 2*radius, 2*radius));
+painter.end();
+//! [0]
+
+Q_UNUSED(event);
+}
+} // plaintextlayout

src/gui/doc/snippets/snippets.pro

@@ -12,6 +12,7 @@ contains(QT_BUILD_PARTS, tests) {
         droprectangle \
         image \
         picture \
+        plaintextlayout \
         qfontdatabase \
         textblock-formats \
         textblock-fragments \