Deprecate download type

This patch removes the download type property from QtWebEngineCore and replaces
it with a simple boolean 'isSavePageDownload'. On the public API boundary the
type property is reimplemented via this boolean and documented as obsolete.

Rationale being that

  1. This feature seems to lack practical use cases, other than perhaps
     distinguishing save-page downloads from normal file downloads, which can be
     done in a much simpler way.

  2. This feature does not work as documented and never has. So far nobody has
     complained, hinting again at a lack of practical use cases.

  3. In order to fix it we would need to maintain patches on top of Chromium and
     Blink (we would, for example, need to propagate the DownloadAttribute type
     from Blink to Chromium to WebEngine).

[ChangeLog][Deprecation Notice] (QWebEngine)DownloadItem::type() is deprecated
and replaced with the newly introduced isSavePageDownload() property.

Task-number: QTBUG-62640
Change-Id: Icf4e1e5a635028986df7eab979f4c0527902ff0c
Reviewed-by: Michal Klocek <michal.klocek@qt.io>

1 files changed, 20 insertions, 13 deletions

diff --git a/src/webengine/api/qquickwebenginedownloaditem.cpp b/src/webengine/api/qquickwebenginedownloaditem.cpp
index 5afb19531..8d7550d6c 100644
--- a/src/webengine/api/qquickwebenginedownloaditem.cpp
+++ b/src/webengine/api/qquickwebenginedownloaditem.cpp
@@ -101,7 +101,7 @@ QQuickWebEngineDownloadItemPrivate::QQuickWebEngineDownloadItemPrivate(QQuickWeb
     , downloadId(-1)
     , downloadState(QQuickWebEngineDownloadItem::DownloadCancelled)
     , savePageFormat(QQuickWebEngineDownloadItem::UnknownSaveFormat)
-    , type(QQuickWebEngineDownloadItem::Attachment)
+    , isSavePageDownload(false)
     , interruptReason(QQuickWebEngineDownloadItem::NoReason)
     , totalBytes(-1)
     , receivedBytes(0)
@@ -397,26 +397,33 @@ void QQuickWebEngineDownloadItem::setSavePageFormat(QQuickWebEngineDownloadItem:
     \qmlproperty enumeration WebEngineDownloadItem::type
     \readonly
     \since QtWebEngine 1.4
+    \obsolete
 
     Describes the requested download's type.
 
-    \value WebEngineDownloadItem.Attachment The web server's response includes a
-           \c Content-Disposition header with the \c attachment directive. If \c Content-Disposition
-           is present in the reply, the web server is indicating that the client should prompt the
-           user to save the content regardless of the content type.
-           See \l {RFC 2616 section 19.5.1} for details.
-    \value WebEngineDownloadItem.DownloadAttribute The user clicked a link with the \c download
-           attribute. See \l {HTML download attribute} for details.
-    \value WebEngineDownloadItem.UserRequested The user initiated the download, for example by
-           selecting a web action.
-    \value WebEngineDownloadItem.SavePage Saving of the current page was requested (for example by
-           the \l{WebEngineView::WebAction}{WebEngineView.SavePage} web action).
+    Unfortunately, this property only ever worked correctly for \c SavePage
+    downloads. In other cases, it followed the documented semantics rather
+    loosely, sometimes non-deterministically. Use \l isSavePageDownload instead.
  */
 
 QQuickWebEngineDownloadItem::DownloadType QQuickWebEngineDownloadItem::type() const
 {
+    return isSavePageDownload() ? SavePage : UserRequested;
+}
+
+/*!
+    \qmlproperty bool WebEngineDownloadItem::isSavePageDownload
+    \readonly
+    \since QtWebEngine 1.7
+
+    Whether this is a download request for saving a web page or a file.
+
+    \sa savePageFormat
+*/
+bool QQuickWebEngineDownloadItem::isSavePageDownload() const
+{
     Q_D(const QQuickWebEngineDownloadItem);
-    return d->type;
+    return d->isSavePageDownload;
 }
 
 /*!