FolderDialog: replace folderSelected() with a declarative property

Follow the same convention that ColorDialog and FontDialog.

Change-Id: I49834daf908aadf145949c0b749c6c066f63fd83
Reviewed-by: J-P Nurmi <jpnurmi@qt.io>

3 files changed, 60 insertions, 46 deletions

diff --git a/src/imports/platform/plugins.qmltypes b/src/imports/platform/plugins.qmltypes
index d751e45f..d7e85c9e 100644
--- a/src/imports/platform/plugins.qmltypes
+++ b/src/imports/platform/plugins.qmltypes
@@ -132,18 +132,11 @@ Module {
         prototype: "QQuickPlatformDialog"
         exports: ["Qt.labs.platform/FolderDialog 1.0"]
         exportMetaObjectRevisions: [0]
+        Property { name: "folder"; type: "QUrl" }
         Property { name: "currentFolder"; type: "QUrl" }
         Property { name: "options"; type: "QFileDialogOptions::FileDialogOptions" }
         Property { name: "acceptLabel"; type: "string" }
         Property { name: "rejectLabel"; type: "string" }
-        Signal {
-            name: "folderSelected"
-            Parameter { name: "folder"; type: "QUrl" }
-        }
-        Signal {
-            name: "foldersSelected"
-            Parameter { name: "folders"; type: "QList<QUrl>" }
-        }
     }
     Component {
         name: "QQuickPlatformFontDialog"
diff --git a/src/imports/platform/qquickplatformfolderdialog.cpp b/src/imports/platform/qquickplatformfolderdialog.cpp
index 04c39f6f..7aa0a7e9 100644
--- a/src/imports/platform/qquickplatformfolderdialog.cpp
+++ b/src/imports/platform/qquickplatformfolderdialog.cpp
@@ -59,9 +59,10 @@ QT_BEGIN_NAMESPACE
     \image qtlabsplatform-folderdialog-gtk.png
 
     To show a folder dialog, construct an instance of FolderDialog, set the
-    desired properties, and call \l {Dialog::}{open()}. FolderDialog emits
-    the \l folderSelected() and \l foldersSelected() signals when the user
-    has selected folder(s).
+    desired properties, and call \l {Dialog::}{open()}. The \l currentFolder
+    property can be used to determine the currently selected folder in the
+    dialog. The \l folder property is updated only after the final selection
+    has been made by accepting the dialog.
 
     \code
     MenuItem {
@@ -72,7 +73,11 @@ QT_BEGIN_NAMESPACE
     FolderDialog {
         id: folderDialog
         currentFolder: viewer.folder
-        onFolderSelected: viewer.folder = folder
+    }
+
+    MyViewer {
+        id: viewer
+        folder: folderDialog.folder
     }
     \endcode
 
@@ -95,29 +100,41 @@ QT_BEGIN_NAMESPACE
     \sa FileDialog
 */
 
-/*!
-    \qmlsignal void Qt.labs.platform::FolderDialog::folderSelected(url folder)
-
-    This signal is emitted when a \a folder has been selected.
+Q_DECLARE_LOGGING_CATEGORY(qtLabsPlatformDialogs)
 
-    \sa foldersSelected(), currentFolder
-*/
+QQuickPlatformFolderDialog::QQuickPlatformFolderDialog(QObject *parent)
+    : QQuickPlatformDialog(parent), m_options(QFileDialogOptions::create())
+{
+    m_options->setFileMode(QFileDialogOptions::Directory);
+    m_options->setAcceptMode(QFileDialogOptions::AcceptOpen);
+}
 
 /*!
-    \qmlsignal void Qt.labs.platform::FolderDialog::foldersSelected(list<url> folders)
+    \qmlproperty url Qt.labs.platform::FolderDialog::folder
 
-    This signal is emitted when multiple \a folders have been selected.
+    This property holds the final accepted folder.
 
-    \sa folderSelected(), currentFolder
-*/
+    Unlike the \l currentFolder property, the \c folder property is not updated
+    while the user is selecting folders in the dialog, but only after the final
+    selection has been made. That is, when the user has clicked \uicontrol OK
+    to accept a folder. Alternatively, the \l {Dialog::}{accepted()} signal
+    can be handled to get the final selection.
 
-Q_DECLARE_LOGGING_CATEGORY(qtLabsPlatformDialogs)
+    \sa currentFolder, {Dialog::}{accepted()}
+*/
+QUrl QQuickPlatformFolderDialog::folder() const
+{
+    return m_folder;
+}
 
-QQuickPlatformFolderDialog::QQuickPlatformFolderDialog(QObject *parent)
-    : QQuickPlatformDialog(parent), m_options(QFileDialogOptions::create())
+void QQuickPlatformFolderDialog::setFolder(const QUrl &folder)
 {
-    m_options->setFileMode(QFileDialogOptions::Directory);
-    m_options->setAcceptMode(QFileDialogOptions::AcceptOpen);
+    if (m_folder == folder)
+        return;
+
+    m_folder = folder;
+    setCurrentFolder(folder);
+    emit folderChanged();
 }
 
 /*!
@@ -125,15 +142,17 @@ QQuickPlatformFolderDialog::QQuickPlatformFolderDialog(QObject *parent)
 
     This property holds the currently selected folder in the dialog.
 
-    \sa folderSelected(), foldersSelected()
+    Unlike the \l folder property, the \c currentFolder property is updated
+    while the user is selecting folders in the dialog, even before the final
+    selection has been made.
+
+    \sa folder
 */
 QUrl QQuickPlatformFolderDialog::currentFolder() const
 {
-    if (m_current.isEmpty()) {
-        if (QPlatformFileDialogHelper *fileDialog = qobject_cast<QPlatformFileDialogHelper *>(handle()))
-            m_current = fileDialog->directory();
-    }
-    return m_current;
+    if (QPlatformFileDialogHelper *fileDialog = qobject_cast<QPlatformFileDialogHelper *>(handle()))
+        return fileDialog->directory();
+    return QUrl();
 }
 
 void QQuickPlatformFolderDialog::setCurrentFolder(const QUrl &folder)
@@ -249,14 +268,7 @@ QPlatformDialogHelper *QQuickPlatformFolderDialog::createHelper()
     qCDebug(qtLabsPlatformDialogs) << "FolderDialog:" << dialog;
 
     if (QPlatformFileDialogHelper *fileDialog = qobject_cast<QPlatformFileDialogHelper *>(dialog)) {
-        connect(fileDialog, &QPlatformFileDialogHelper::fileSelected, this, &QQuickPlatformFolderDialog::folderSelected);
-        connect(fileDialog, &QPlatformFileDialogHelper::filesSelected, this, &QQuickPlatformFolderDialog::foldersSelected);
-        connect(fileDialog, &QPlatformFileDialogHelper::currentChanged, [this](const QUrl &url) {
-            if (m_current == url)
-                return;
-            m_current = url;
-            emit currentFolderChanged();
-        });
+        connect(fileDialog, &QPlatformFileDialogHelper::directoryEntered, this, &QQuickPlatformFolderDialog::currentFolderChanged);
         fileDialog->setOptions(m_options);
     }
     return dialog;
@@ -267,4 +279,10 @@ void QQuickPlatformFolderDialog::applyOptions()
     m_options->setWindowTitle(title());
 }
 
+void QQuickPlatformFolderDialog::accept()
+{
+    setFolder(currentFolder());
+    QQuickPlatformDialog::accept();
+}
+
 QT_END_NAMESPACE
diff --git a/src/imports/platform/qquickplatformfolderdialog_p.h b/src/imports/platform/qquickplatformfolderdialog_p.h
index 39dc025f..2c0fdf51 100644
--- a/src/imports/platform/qquickplatformfolderdialog_p.h
+++ b/src/imports/platform/qquickplatformfolderdialog_p.h
@@ -57,6 +57,7 @@ QT_BEGIN_NAMESPACE
 class QQuickPlatformFolderDialog : public QQuickPlatformDialog
 {
     Q_OBJECT
+    Q_PROPERTY(QUrl folder READ folder WRITE setFolder NOTIFY folderChanged FINAL)
     Q_PROPERTY(QUrl currentFolder READ currentFolder WRITE setCurrentFolder NOTIFY currentFolderChanged FINAL)
     Q_PROPERTY(QFileDialogOptions::FileDialogOptions options READ options WRITE setOptions RESET resetOptions NOTIFY optionsChanged FINAL)
     Q_PROPERTY(QString acceptLabel READ acceptLabel WRITE setAcceptLabel RESET resetAcceptLabel NOTIFY acceptLabelChanged FINAL)
@@ -66,8 +67,11 @@ class QQuickPlatformFolderDialog : public QQuickPlatformDialog
 public:
     explicit QQuickPlatformFolderDialog(QObject *parent = nullptr);
 
+    QUrl folder() const;
+    void setFolder(const QUrl &folder);
+
     QUrl currentFolder() const;
-    void setCurrentFolder(const QUrl &url);
+    void setCurrentFolder(const QUrl &folder);
 
     QFileDialogOptions::FileDialogOptions options() const;
     void setOptions(QFileDialogOptions::FileDialogOptions options);
@@ -82,20 +86,19 @@ public:
     void resetRejectLabel();
 
 Q_SIGNALS:
+    void folderChanged();
     void currentFolderChanged();
     void optionsChanged();
     void acceptLabelChanged();
     void rejectLabelChanged();
 
-    void folderSelected(const QUrl &folder);
-    void foldersSelected(const QList<QUrl> &folders);
-
 protected:
     QPlatformDialogHelper *createHelper() override;
     void applyOptions() override;
+    void accept() override;
 
 private:
-    mutable QUrl m_current;
+    QUrl m_folder;
     QSharedPointer<QFileDialogOptions> m_options;
 };