Brush up the drop site example

- Use qsizetype
- Use new string literals instead of deprecated QLatin1String()
- Streamline some code
- Remove unused member variable
- Remove module include

Pick-to: 6.4
Change-Id: Ia96424a23f3ae10e57db942de49949ce3aef8876
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>

examples/widgets/doc/dropsite.qdoc

@@ -25,8 +25,8 @@
 
     \snippet draganddrop/dropsite/droparea.h DropArea header part1
 
-    In addition, \c DropArea also contains a private instance of QLabel and
-    reimplementations of four \l{QWidget} event handlers:
+    In addition, \c DropArea contains reimplementations of four \l{QWidget}
+    event handlers:
 
     \list 1
         \li \l{QWidget::dragEnterEvent()}{dragEnterEvent()}

examples/widgets/draganddrop/dropsite/droparea.cpp

@@ -6,6 +6,8 @@
 #include <QDragEnterEvent>
 #include <QMimeData>
 
+using namespace Qt::StringLiterals;
+
 //! [DropArea constructor]
 DropArea::DropArea(QWidget *parent)
     : QLabel(parent)
@@ -46,8 +48,8 @@ void DropArea::dropEvent(QDropEvent *event)
 //! [dropEvent() function part2]
     if (mimeData->hasImage()) {
         setPixmap(qvariant_cast<QPixmap>(mimeData->imageData()));
-    } else if (mimeData->hasFormat(QLatin1String("text/markdown"))) {
-        setText(QString::fromUtf8(mimeData->data(QLatin1String("text/markdown"))));
+    } else if (mimeData->hasFormat(u"text/markdown"_s)) {
+        setText(QString::fromUtf8(mimeData->data(u"text/markdown"_s)));
         setTextFormat(Qt::MarkdownText);
     } else if (mimeData->hasHtml()) {
         setText(mimeData->html());
@@ -58,8 +60,8 @@ void DropArea::dropEvent(QDropEvent *event)
     } else if (mimeData->hasUrls()) {
         QList<QUrl> urlList = mimeData->urls();
         QString text;
-        for (int i = 0; i < urlList.size() && i < 32; ++i)
-            text += urlList.at(i).path() + QLatin1Char('\n');
+        for (qsizetype i = 0, count = qMin(urlList.size(), qsizetype(32)); i < count; ++i)
+            text += urlList.at(i).path() + u'\n';
         setText(text);
     } else {
         setText(tr("Cannot display data"));

examples/widgets/draganddrop/dropsite/droparea.h

@@ -31,9 +31,6 @@ protected:
     void dragMoveEvent(QDragMoveEvent *event) override;
     void dragLeaveEvent(QDragLeaveEvent *event) override;
     void dropEvent(QDropEvent *event) override;
-
-private:
-    QLabel *label;
 };
 //! [DropArea header part2]
 

examples/widgets/draganddrop/dropsite/dropsitewindow.cpp

@@ -1,11 +1,23 @@
 // Copyright (C) 2016 The Qt Company Ltd.
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
 
-#include <QtWidgets>
+#include <QPushButton>
+#include <QDialogButtonBox>
+#include <QHeaderView>
+#include <QTableWidget>
+#include <QTableWidgetItem>
+#include <QVBoxLayout>
+
+#include <QClipboard>
+#include <QGuiApplication>
+
+#include <QMimeData>
 
 #include "droparea.h"
 #include "dropsitewindow.h"
 
+using namespace Qt::StringLiterals;
+
 //! [constructor part1]
 DropSiteWindow::DropSiteWindow()
 {
@@ -23,13 +35,10 @@ DropSiteWindow::DropSiteWindow()
 //! [constructor part2]
 
 //! [constructor part3]
-    QStringList labels;
-    labels << tr("Format") << tr("Content");
-
     formatsTable = new QTableWidget;
     formatsTable->setColumnCount(2);
     formatsTable->setEditTriggers(QAbstractItemView::NoEditTriggers);
-    formatsTable->setHorizontalHeaderLabels(labels);
+    formatsTable->setHorizontalHeaderLabels({tr("Format"),  tr("Content")});
     formatsTable->horizontalHeader()->setStretchLastSection(true);
 //! [constructor part3]
 
@@ -60,7 +69,7 @@ DropSiteWindow::DropSiteWindow()
     mainLayout->addWidget(buttonBox);
 
     setWindowTitle(tr("Drop Site"));
-    setMinimumSize(350, 500);
+    resize(700, 500);
 }
 //! [constructor part5]
 
@@ -83,20 +92,21 @@ void DropSiteWindow::updateFormatsTable(const QMimeData *mimeData)
 
 //! [updateFormatsTable() part3]
         QString text;
-        if (format == QLatin1String("text/plain")) {
+        if (format == u"text/plain") {
             text = mimeData->text().simplified();
-        } else if (format == QLatin1String("text/markdown")) {
-            text = QString::fromUtf8(mimeData->data(QLatin1String("text/markdown")));
-        } else if (format == QLatin1String("text/html")) {
+        } else if (format == u"text/markdown") {
+            text = QString::fromUtf8(mimeData->data(u"text/markdown"_s));
+        } else if (format == u"text/html") {
             text = mimeData->html().simplified();
-        } else if (format == QLatin1String("text/uri-list")) {
+        } else if (format == u"text/uri-list") {
             QList<QUrl> urlList = mimeData->urls();
-            for (int i = 0; i < urlList.size() && i < 32; ++i)
-                text.append(urlList.at(i).toString() + QLatin1Char(' '));
+            for (qsizetype i = 0, count = qMin(urlList.size(), qsizetype(32)); i < count; ++i)
+                text.append(urlList.at(i).toString() + u' ');
         } else {
             QByteArray data = mimeData->data(format);
-            for (int i = 0; i < data.size() && i < 32; ++i)
-                text.append(QStringLiteral("%1 ").arg(uchar(data[i]), 2, 16, QLatin1Char('0')).toUpper());
+            if (data.size() > 32)
+                data.truncate(32);
+            text = QString::fromLatin1(data.toHex(' ')).toUpper();
         }
 //! [updateFormatsTable() part3]