Merge pull request #5392 from nyalldawson/file_downloader

Split QgsFileDownloader into separate core/gui classes

Author: nyalldawson

doc/api_break.dox

@@ -1253,6 +1253,15 @@ QgsFieldProxyModel        {#qgis_api_break_3_0_QgsFieldProxyModel}
 - In QgsFieldProxyModel::Filter, All has been renamed to AllTypes
 
 
+QgsFileDownloader       {#qgis_api_break_3_0_QgsFileDownloader}
+-----------------
+
+- In 2.x QgsFileDownloader was a gui library class. In 3.0 its functionality has been split into
+two new classes - a core QgsFileDownloader class, which handles just the file download functionality
+and contains no GUI progress bar dialog, and a separate QgsFileDownloaderDialog class which
+incorporates a QgsFileDownloader together with a user-visible progress bar dialog
+
+
 QgsGeometry        {#qgis_api_break_3_0_QgsGeometry}
 -----------
 

python/core/core_auto.sip

@@ -310,6 +310,7 @@
 %Include qgsfieldformatterregistry.sip
 %Include qgsfieldmodel.sip
 %Include qgsfieldproxymodel.sip
+%Include qgsfiledownloader.sip
 %Include qgsgeometryvalidator.sip
 %Include qgsgml.sip
 %Include qgsgmlschema.sip

python/gui/qgsfiledownloader.sip renamed to python/core/qgsfiledownloader.sip

@@ -1,7 +1,7 @@
 /************************************************************************
  * This file has been generated automatically from                      *
  *                                                                      *
- * src/gui/qgsfiledownloader.h                                          *
+ * src/core/qgsfiledownloader.h                                         *
  *                                                                      *
  * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
  ************************************************************************/
@@ -16,29 +16,33 @@ class QgsFileDownloader : QObject
 
  To use this class, it is necessary to pass the URL and an output file name as
  arguments to the constructor, the download will start immediately.
- The download is asynchronous and depending on the guiNotificationsEnabled
- parameter accepted by the constructor (default = true) the class will
- show a progress dialog and report all errors in a QMessageBox.warning dialog.
- If the guiNotificationsEnabled parameter is set to false, the class can still
- be used through the signals and slots mechanism.
+
+ The download is asynchronous.
+
  The object will destroy itself when the request completes, errors or is canceled.
  An optional authentication configuration can be specified.
 
-.. versionadded:: 2.18.1
+.. note::
+
+   This class was part of the GUI library from QGIS 2.18.1 until QGIS 3.0
+.. versionadded:: 3.0
 %End
 
 %TypeHeaderCode
 #include "qgsfiledownloader.h"
 %End
   public:
 
-    QgsFileDownloader( const QUrl &url, const QString &outputFileName, bool guiNotificationsEnabled = true, const QString &authcfg = QString() );
+    QgsFileDownloader( const QUrl &url, const QString &outputFileName, const QString &authcfg = QString(), bool delayStart = false );
 %Docstring
  QgsFileDownloader
  \param url the download url
  \param outputFileName file name where the downloaded content will be stored
- \param guiNotificationsEnabled if false, the downloader will not display any progress bar or error message
  \param authcfg optionally apply this authentication configuration
+ \param delayStart if true, the download will not be commenced immediately and must
+ be triggered by a later call to startDownload(). This can be useful if connections need
+ to be made to the downloader and there's a chance the download will emit
+ signals before these connections have been made.
 %End
 
   signals:
@@ -50,10 +54,13 @@ Emitted when the download has completed successfully
 %Docstring
 Emitted always when the downloader exits
 %End
+
     void downloadCanceled();
 %Docstring
-Emitted when the download was canceled by the user
+ Emitted when the download was canceled by the user.
+.. seealso:: cancelDownload()
 %End
+
     void downloadError( QStringList errorMessages );
 %Docstring
 Emitted when an error makes the download fail
@@ -65,13 +72,16 @@ Emitted when data are ready to be processed
 
   public slots:
 
-    void onDownloadCanceled();
+    void cancelDownload();
+%Docstring
+ Call to abort the download and delete this object after the cancelation
+ has been processed.
+.. seealso:: downloadCanceled()
+%End
+
+    void startDownload();
 %Docstring
- Called when a download is canceled by the user
- this slot aborts the download and deletes
- the object.
- Never call this slot directly: this is meant to
- be managed by the signal-slot system.
+Called to start the download
 %End
 
   protected:
@@ -82,7 +92,7 @@ Emitted when data are ready to be processed
 /************************************************************************
  * This file has been generated automatically from                      *
  *                                                                      *
- * src/gui/qgsfiledownloader.h                                          *
+ * src/core/qgsfiledownloader.h                                         *
  *                                                                      *
  * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
  ************************************************************************/

python/gui/gui_auto.sip

@@ -18,7 +18,6 @@
 %Include qgsuserinputdockwidget.sip
 %Include qgsbrowserdockwidget.sip
 %Include qgsvertexmarker.sip
-%Include qgsfiledownloader.sip
 %Include qgsabstractdatasourcewidget.sip
 %Include qgssourceselectprovider.sip
 %Include qgssourceselectproviderregistry.sip
@@ -201,6 +200,7 @@
 %Include qgstreewidgetitem.sip
 %Include qgsunitselectionwidget.sip
 %Include qgsvariableeditorwidget.sip
+%Include qgsfiledownloaderdialog.sip
 %Include raster/qgsmultibandcolorrendererwidget.sip
 %Include raster/qgspalettedrendererwidget.sip
 %Include raster/qgsrasterbandcombobox.sip

python/gui/qgsfiledownloaderdialog.sip

@@ -0,0 +1,72 @@
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/gui/qgsfiledownloaderdialog.h                                    *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/
+
+
+
+
+class QgsFileDownloaderDialog : QProgressDialog
+{
+%Docstring
+ QgsFileDownloaderDialog is a QProgressDialog subclass which
+ handles file downloads and user feedback.
+
+ Internally, it uses QgsFileDownloader to handle the download,
+ while showing progress via a progress dialog and supporting
+ cancelation.
+
+.. note::
+
+   Until QGIS 3.0 this functionality was available via QgsFileDownloader.
+
+.. versionadded:: 3.0
+%End
+
+%TypeHeaderCode
+#include "qgsfiledownloaderdialog.h"
+%End
+  public:
+
+    QgsFileDownloaderDialog( const QUrl &url, const QString &outputFileName, const QString &authcfg = QString() );
+%Docstring
+ QgsFileDownloader
+ \param url the download url
+ \param outputFileName file name where the downloaded content will be stored
+ \param authcfg optionally apply this authentication configuration
+%End
+
+  signals:
+    void downloadCompleted();
+%Docstring
+Emitted when the download has completed successfully
+%End
+    void downloadExited();
+%Docstring
+Emitted always when the downloader exits
+%End
+    void downloadCanceled();
+%Docstring
+Emitted when the download was canceled by the user
+%End
+    void downloadError( QStringList errorMessages );
+%Docstring
+Emitted when an error makes the download fail
+%End
+    void downloadProgress( qint64 bytesReceived, qint64 bytesTotal );
+%Docstring
+Emitted when data are ready to be processed
+%End
+
+};
+
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/gui/qgsfiledownloaderdialog.h                                    *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/

src/app/qgsidentifyresultsdialog.cpp

@@ -42,7 +42,7 @@
 #include "qgswebframe.h"
 #include "qgsstringutils.h"
 #include "qgstreewidgetitem.h"
-#include "qgsfiledownloader.h"
+#include "qgsfiledownloaderdialog.h"
 #include "qgsfieldformatterregistry.h"
 #include "qgsfieldformatter.h"
 #include "qgssettings.h"
@@ -132,7 +132,7 @@ void QgsIdentifyResultsWebView::handleDownload( QUrl url )
     {
       settings.setValue( DOWNLOADER_LAST_DIR_KEY, QFileInfo( targetFile ).dir().absolutePath() );
       // Start the download
-      new QgsFileDownloader( url, targetFile );
+      new QgsFileDownloaderDialog( url, targetFile );
     }
   }
 }

src/core/CMakeLists.txt

@@ -182,6 +182,7 @@ SET(QGIS_CORE_SRCS
   qgsfieldmodel.cpp
   qgsfieldproxymodel.cpp
   qgsfields.cpp
+  qgsfiledownloader.cpp
   qgsfontutils.cpp
   qgsgeometrysimplifier.cpp
   qgsgeometryvalidator.cpp
@@ -588,6 +589,7 @@ SET(QGIS_CORE_MOC_HDRS
   qgsfieldformatterregistry.h
   qgsfieldmodel.h
   qgsfieldproxymodel.h
+  qgsfiledownloader.h
   qgsgeometryvalidator.h
   qgsgml.h
   qgsgmlschema.h

src/gui/qgsfiledownloader.cpp renamed to src/core/qgsfiledownloader.cpp

@@ -21,19 +21,18 @@
 #include <QNetworkAccessManager>
 #include <QNetworkRequest>
 #include <QNetworkReply>
-#include <QMessageBox>
 #ifndef QT_NO_SSL
 #include <QSslError>
 #endif
 
-QgsFileDownloader::QgsFileDownloader( const QUrl &url, const QString &outputFileName, bool enableGuiNotifications, const QString &authcfg )
+QgsFileDownloader::QgsFileDownloader( const QUrl &url, const QString &outputFileName, const QString &authcfg, bool delayStart )
   : mUrl( url )
   , mDownloadCanceled( false )
-  , mGuiNotificationsEnabled( enableGuiNotifications )
 {
   mFile.setFileName( outputFileName );
   mAuthCfg = authcfg;
-  startDownload();
+  if ( !delayStart )
+    startDownload();
 }
 
 
@@ -44,10 +43,6 @@ QgsFileDownloader::~QgsFileDownloader()
     mReply->abort();
     mReply->deleteLater();
   }
-  if ( mProgressDialog )
-  {
-    mProgressDialog->deleteLater();
-  }
 }
 
 
@@ -83,17 +78,9 @@ void QgsFileDownloader::startDownload()
 #ifndef QT_NO_SSL
   connect( nam, &QgsNetworkAccessManager::sslErrors, this, &QgsFileDownloader::onSslErrors, Qt::UniqueConnection );
 #endif
-  if ( mGuiNotificationsEnabled )
-  {
-    mProgressDialog = new QProgressDialog();
-    mProgressDialog->setWindowTitle( tr( "Download" ) );
-    mProgressDialog->setLabelText( tr( "Downloading %1." ).arg( mFile.fileName() ) );
-    mProgressDialog->show();
-    connect( mProgressDialog, &QProgressDialog::canceled, this, &QgsFileDownloader::onDownloadCanceled );
-  }
 }
 
-void QgsFileDownloader::onDownloadCanceled()
+void QgsFileDownloader::cancelDownload()
 {
   mDownloadCanceled = true;
   emit downloadCanceled();
@@ -126,11 +113,6 @@ void QgsFileDownloader::error( const QStringList &errorMessages )
   {
     mErrors << errorMessages[i];
   }
-  // Show error
-  if ( mGuiNotificationsEnabled )
-  {
-    QMessageBox::warning( nullptr, tr( "Download failed" ), mErrors.join( QStringLiteral( "<br>" ) ) );
-  }
   emit downloadError( mErrors );
 }
 
@@ -142,7 +124,12 @@ void QgsFileDownloader::error( const QString &errorMessage )
 void QgsFileDownloader::onReadyRead()
 {
   Q_ASSERT( mReply );
-  if ( ! mFile.isOpen() && ! mFile.open( QIODevice::WriteOnly | QIODevice::Truncate ) )
+  if ( mFile.fileName().isEmpty() )
+  {
+    error( tr( "No output filename specified" ) );
+    onFinished();
+  }
+  else if ( ! mFile.isOpen() && ! mFile.open( QIODevice::WriteOnly | QIODevice::Truncate ) )
   {
     error( tr( "Cannot open output file: %1" ).arg( mFile.fileName() ) );
     onFinished();
@@ -159,18 +146,19 @@ void QgsFileDownloader::onFinished()
   // when canceled
   if ( ! mErrors.isEmpty() || mDownloadCanceled )
   {
-    mFile.close();
-    mFile.remove();
-    if ( mGuiNotificationsEnabled )
-      mProgressDialog->hide();
+    if ( mFile.isOpen() )
+      mFile.close();
+    if ( mFile.exists() )
+      mFile.remove();
   }
   else
   {
     // download finished normally
-    if ( mGuiNotificationsEnabled )
-      mProgressDialog->hide();
-    mFile.flush();
-    mFile.close();
+    if ( mFile.isOpen() )
+    {
+      mFile.flush();
+      mFile.close();
+    }
 
     // get redirection url
     QVariant redirectionTarget = mReply->attribute( QNetworkRequest::RedirectionTargetAttribute );
@@ -206,11 +194,6 @@ void QgsFileDownloader::onDownloadProgress( qint64 bytesReceived, qint64 bytesTo
   {
     return;
   }
-  if ( mGuiNotificationsEnabled )
-  {
-    mProgressDialog->setMaximum( bytesTotal );
-    mProgressDialog->setValue( bytesReceived );
-  }
   emit downloadProgress( bytesReceived, bytesTotal );
 }