Introduce QUrlResourceProvider to load resources for HTML

QTextDocument and the text editor classes suggest to override
their loadResource() methods to provide data associated with
a text document. This approach has the following drawbacks:
- it requires subclassing
- there is no way to set a global resource provider
- QLabel is missing virtual loadResource() method and
  it can't be added without breaking ABI

QUrlResourceProvider is designed to solve these issues.
One should create a derived class that implements
QUrlResourceProvider::resource(). The objects of the derived
class then can be set for any text document.
The default resource provider can be set with
QUrlResourceProvider::setDefaultProvider().
This change also adds QLabel::setResourceProvider(),
which doesn't break ABI.

[ChangeLog][QtGui][Text] Introduced QUrlResourceProvider that allows to
load resources for HTML. It is intended to replace the use of
QTextDocument::loadResource().

Change-Id: Iaf19b229f522a73508f20715257450fe58f68daf
Reviewed-by: Konstantin Ritt <ritt.ks@gmail.com>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

1 files changed, 4 insertions, 0 deletions

diff --git a/src/gui/text/qtextdocument.h b/src/gui/text/qtextdocument.h
index 23fffc4771..ea57b697a8 100644
--- a/src/gui/text/qtextdocument.h
+++ b/src/gui/text/qtextdocument.h
@@ -68,6 +68,7 @@ class QVariant;
 class QRectF;
 class QTextOption;
 class QTextCursor;
+class QUrlResourceProvider;
 
 
 namespace Qt
@@ -239,6 +240,9 @@ public:
     QVariant resource(int type, const QUrl &name) const;
     void addResource(int type, const QUrl &name, const QVariant &resource);
 
+    QUrlResourceProvider *resourceProvider() const;
+    void setResourceProvider(QUrlResourceProvider *provider);
+
     QList<QTextFormat> allFormats() const;
 
     void markContentsDirty(int from, int length);