Adapt the widgetbinding example

Port qtbase/4a5abfcea4ec2e494efd117d278a929f020816c0, fixing
the C++ code to handle UCS4 Emojis correctly.

Task-number: PYSIDE-2206
Change-Id: Ia5cdf7e6579b1400dc16ca47ec2adcd6cfe66877
Reviewed-by: Christian Tismer <tismer@stackless.com>

2 files changed, 9 insertions, 6 deletions

diff --git a/examples/widgetbinding/dialog.py b/examples/widgetbinding/dialog.py
index 20dbd476c..1bd127804 100644
--- a/examples/widgetbinding/dialog.py
+++ b/examples/widgetbinding/dialog.py
@@ -21,12 +21,13 @@ class Dialog(QDialog):
         layout.addWidget(wiggly_widget_py)
         layout.addWidget(wiggly_widget_cpp)
         layout.addWidget(lineEdit)
+        lineEdit.setClearButtonEnabled(True)
         wiggly_widget_py.running = True
         wiggly_widget_cpp.setRunning(True)
 
         lineEdit.textChanged.connect(wiggly_widget_py.setText)
         lineEdit.textChanged.connect(wiggly_widget_cpp.setText)
-        lineEdit.setText("Hello world!")
+        lineEdit.setText("🖖 Hello world!")
 
         self.setWindowTitle("Wiggly")
         self.resize(360, 145)
diff --git a/examples/widgetbinding/wigglywidget.cpp b/examples/widgetbinding/wigglywidget.cpp
index 79fc79ee4..6fdc65f39 100644
--- a/examples/widgetbinding/wigglywidget.cpp
+++ b/examples/widgetbinding/wigglywidget.cpp
@@ -39,14 +39,16 @@ void WigglyWidget::paintEvent(QPaintEvent * /* event */)
 //! [3]
     QPainter painter(this);
 //! [3] //! [4]
-    for (int i = 0; i < m_text.size(); ++i) {
-        int index = (m_step + i) % 16;
+    int offset = 0;
+    const auto codePoints = m_text.toUcs4();
+    for (char32_t codePoint : codePoints) {
+        const int index = (m_step + offset++) % 16;
         color.setHsv((15 - index) * 16, 255, 191);
         painter.setPen(color);
-        const QChar c = m_text.at(i);
+        QString symbol = QString::fromUcs4(&codePoint, 1);
         const int dy = (sineTable[index] * metrics.height()) / 400;
-        painter.drawText(x, y - dy, c);
-        x += metrics.horizontalAdvance(c);
+        painter.drawText(x, y - dy, symbol);
+        x += metrics.horizontalAdvance(symbol);
     }
 }
 //! [4]