[ Solved ] [ iOS ] How to open a custom file extension using "Open in MyApp" ?

[Eddie]

I have a Qt 5.5 widget app.

After adding UTExportedTypeDeclarations and CFBundleDocumentTypes sections to my Info.plist, I can now open a file attachment in Apple Mail and select "Open in MyApp" then MyApp launches.

How can I receive the file and open it? Has anyone figured this out?

I see openURL and didFinishLaunchingWithOptions being discussed.

• (BOOL)application:(UIApplication *)application openURL:(NSURL *)url sourceApplication:(NSString *)sourceApplication annotation:(id)annotation
  {
  // handle the URL here
  }

The LaunchMe Example uses OpenURL.
https://developer.apple.com/library/ios/samplecode/LaunchMe/Introduction/Intro.html

How to do same in Qt seems challenging.

Thanks in advance for any tips,

-Ed

[Eddie]

Ben Lau on Qt Interest mailing list explained that Objective-C categories can be used to override classes even if you do not have the header file.

I do not understand how. The following somehow works without having to initialize it to the instance of UIApplication.

I put a breakpoint in openURL. When I open an email attachment, my app is launched, and the breakpoint is hit. Magic.

File: myappdelegate.mm

#include <UIKit/UIKit.h>

#include "qiosapplicationdelegate.h"

#include "mainwindow.h"

@implementation QIOSApplicationDelegate (CmsApplicationDelegate)

• (BOOL)application:(UIApplication *)application openURL:(NSURL *)url
  sourceApplication:(NSString *)sourceApplication
  annotation:(id)annotation
  {
  Q_UNUSED(application);
  Q_UNUSED(annotation);

  NSLog(@"sourceApplication: %@",sourceApplication);
  NSLog(@"url: %@",url);

  // A bit of ugly code involving adding a static instance method and a static variable
  // But it works!
  //
  cms::MainWindow* mainWindow = cms::MainWindow::instance();
  if(0 != mainWindow)
  {
  QString filePath = QString::fromNSString(url.path);
  qDebug("filePath %s", filePath.toLatin1().data());
  mainWindow->openFile(filePath);
  }

  return YES;
  }
  @end

I added an INCLUDEPATH to my project file.

File: myapp.pro

ios {
QTBASE=$$clean_path($$QMAKE_QMAKE/../../..)/Src/qtbase
INCLUDEPATH += $$QTBASE/src/plugins/platforms/ios
}

-Ed

[Eddie]

This post is deleted!

[Eddie]

I found a solution I like better that posts a QFileOpenEvent.

I like it better because in order to handle file open on OS X I had to subclass QApplication and give it a pointer to my MainWindow to handle the QFileOpenEvent. Now my OS X and iOS implementation are similar and easier to maintain.

File: cmsapplication.h

<pre>
#include <UIKit/UIKit.h>

#include <QDebug>
#include <QFileOpenEvent>

#include "qiosapplicationdelegate.h"

/// \category QIOSApplicationDelegate(CmsApplicationDelegate)
/// \abstract A category on QIOSApplicationDelegate to override openURL

/// Use the Objective-C category feature to override the openURL method
@implementation QIOSApplicationDelegate (CmsApplicationDelegate)

/// Posts a QFileOpenEvent to QCoreApplication when iOS calls openURL.
///
/// This allows userto open a TSR file from Apple Mail,
/// select "Open in TSR", to launch TSR and pass openURL the
/// file to open.
///
/// Must add UTExportedTypeDeclarations and CFBundleDocumentTypes to your
/// Info.plist for this to work.
///
/// Example: Info.plist
/// \verbatim
/// <key>UTExportedTypeDeclarations</key>
/// <array>
/// <dict>
/// <key>UTTypeConformsTo</key>
/// <array>
/// <string>public.data</string>
/// </array>
/// <key>UTTypeDescription</key>
/// <string>Tracking Status Report</string>
/// <key>UTTypeIdentifier</key>
/// <string>com.ditchwitch.tsr</string>
/// <key>UTTypeTagSpecification</key>
/// <dict>
/// <key>public.filename-extension</key>
/// <string>tsr</string>
/// <key>public.mime-type</key>
/// <string>public.data</string>
/// </dict>
/// </dict>
/// </array>
/// <key>CFBundleDocumentTypes</key>
/// <array>
/// <dict>
/// <key>CFBundleTypeIconFiles</key>
/// <array>
/// <string>Icon.png</string>
/// </array>
/// <key>CFBundleTypeName</key>
/// <string>Tracking Status Report</string>
/// <key>CFBundleTypeRole</key>
/// <string>Editor</string>
/// <key>LSHandlerRank</key>
/// <string>Owner</string>
/// <key>LSItemContentTypes</key>
/// <array>
/// <string>com.ditchwitch.tsr</string>
/// <string>public.data</string>
/// </array>
/// </dict>
/// </array>
/// \endverbatim
///
/// See file: cmsapplication.cpp
/// \see cmsapplication.cpp
///
/// \see https://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/ProgrammingWithObjectiveC/CustomizingExistingClasses/CustomizingExistingClasses.html
///

• (BOOL)application:(UIApplication *)application openURL:(NSURL *)url
  sourceApplication:(NSString *)sourceApplication
  annotation:(id)annotation
  {
  Q_UNUSED(application);
  Q_UNUSED(annotation);

  NSLog(@"sourceApplication: %@",sourceApplication);
  NSLog(@"url: %@",url);

  QString filePath = QString::fromNSString(url.path);
  qDebug("filePath %s", filePath.toLatin1().data());

  QFileOpenEvent *fileOpenEvent = new QFileOpenEvent(filePath);
  QCoreApplication::postEvent(QCoreApplication::instance(), fileOpenEvent);

  return YES;
  }

@end
</pre>

File: cmsapplication.cpp

// class CmsApplication : public QApplication

<pre>
#if defined(Q_OS_OSX) || defined(Q_OS_IOS)
// Looks for QFileOpenEvent to implement TSR file open from
/// other apps, for example, Finder on OS X, or Apple Mail on iOS and OS X.
///
///
/// \remarks Could this work on Android too?
///
/// See file: cmsapplicationdelegate.mm
/// \see cmsapplicationdelegate.mm
///
bool CmsApplication::event(QEvent* event)
{
qDebug() << event->type();
// iOS receives ApplicationDeactivate, ApllicationStateChange, when Home is pressed
// When iOS user opens Mail file attachment using "Open in TSR", ApplicationActivate event received but NOT QEvent::FileOpen
switch (event->type())
{
case QEvent::ApplicationActivate:
{
//clean();
if (false == m_mainWindow.isMinimized())
{
m_mainWindow.show();
}
return true;
}
case QEvent::FileOpen:
{
QString fileName = static_cast<QFileOpenEvent *>(event)->file();
m_mainWindow.openFile(fileName);
return true;
}
default:
break;
}
return QApplication::event(event);
}
#endif
</pre>