FormEditor: Make it possible to switch from source to form

before designer is fully initialized. The action actually doesn't depend
on designer being initialized, so it can be registered directly at start
up.

Task-number: QTCREATORBUG-11244
Change-Id: I275517befa4dc94714b94a6cd665eb0361a3c45b
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>

src/plugins/designer/formeditorplugin.cpp

@@ -40,10 +40,14 @@
 #include "settingspage.h"
 #include "qtdesignerformclasscodegenerator.h"
 
+#include <coreplugin/actionmanager/actioncontainer.h>
+#include <coreplugin/actionmanager/actionmanager.h>
+#include <coreplugin/editormanager/editormanager.h>
 #include <coreplugin/icore.h>
 #include <coreplugin/mimedatabase.h>
 #include <coreplugin/coreconstants.h>
 #include <coreplugin/designmode.h>
+#include <cpptools/cpptoolsconstants.h>
 
 #include <QDebug>
 #include <QLibraryInfo>
@@ -55,6 +59,7 @@ using namespace Designer::Internal;
 using namespace Designer::Constants;
 
 FormEditorPlugin::FormEditorPlugin()
+    : m_actionSwitchSource(new QAction(tr("Switch Source/Form"), this))
 {
 }
 
@@ -99,6 +104,18 @@ void FormEditorPlugin::extensionsInitialized()
 {
     DesignMode::instance()->setDesignModeIsRequired();
     // 4) test and make sure everything works (undo, saving, editors, opening/closing multiple files, dirtiness etc)
+
+    ActionContainer *mtools = ActionManager::actionContainer(Core::Constants::M_TOOLS);
+    ActionContainer *mformtools = ActionManager::createMenu(M_FORMEDITOR);
+    mformtools->menu()->setTitle(tr("For&m Editor"));
+    mtools->addMenu(mformtools);
+
+    connect(m_actionSwitchSource, SIGNAL(triggered()), this, SLOT(switchSourceForm()));
+    Core::Context context(Designer::Constants::C_FORMEDITOR, Core::Constants::C_EDITORMANAGER);
+    Core::Command *cmd = Core::ActionManager::registerAction(m_actionSwitchSource,
+                                                             "FormEditor.FormSwitchSource", context);
+    cmd->setDefaultKeySequence(tr("Shift+F4"));
+    mformtools->addAction(cmd, Core::Constants::G_DEFAULT_THREE);
 }
 
 ////////////////////////////////////////////////////
@@ -134,4 +151,56 @@ void FormEditorPlugin::initializeTemplates()
 #endif
 }
 
+// Find out current existing editor file
+static QString currentFile()
+{
+    if (const IDocument *document = EditorManager::currentDocument()) {
+        const QString fileName = document->filePath();
+        if (!fileName.isEmpty() && QFileInfo(fileName).isFile())
+            return fileName;
+    }
+    return QString();
+}
+
+// Switch between form ('ui') and source file ('cpp'):
+// Find corresponding 'other' file, simply assuming it is in the same directory.
+static QString otherFile()
+{
+    // Determine mime type of current file.
+    const QString current = currentFile();
+    if (current.isEmpty())
+        return QString();
+    const MimeType currentMimeType = MimeDatabase::findByFile(current);
+    if (!currentMimeType)
+        return QString();
+    // Determine potential suffixes of candidate files
+    // 'ui' -> 'cpp', 'cpp/h' -> 'ui'.
+    QStringList candidateSuffixes;
+    if (currentMimeType.type() == QLatin1String(FORM_MIMETYPE)) {
+        candidateSuffixes += MimeDatabase::findByType(QLatin1String(CppTools::Constants::CPP_SOURCE_MIMETYPE)).suffixes();
+    } else if (currentMimeType.type() == QLatin1String(CppTools::Constants::CPP_SOURCE_MIMETYPE)
+               || currentMimeType.type() == QLatin1String(CppTools::Constants::CPP_HEADER_MIMETYPE)) {
+        candidateSuffixes += MimeDatabase::findByType(QLatin1String(FORM_MIMETYPE)).suffixes();
+    } else {
+        return QString();
+    }
+    // Try to find existing file with desired suffix
+    const QFileInfo currentFI(current);
+    const QString currentBaseName = currentFI.path() + QLatin1Char('/')
+            + currentFI.baseName() + QLatin1Char('.');
+    foreach (const QString &candidateSuffix, candidateSuffixes) {
+        const QFileInfo fi(currentBaseName + candidateSuffix);
+        if (fi.isFile())
+            return fi.absoluteFilePath();
+    }
+    return QString();
+}
+
+void FormEditorPlugin::switchSourceForm()
+{
+    const QString fileToOpen = otherFile();
+    if (!fileToOpen.isEmpty())
+        Core::EditorManager::openEditor(fileToOpen);
+}
+
 Q_EXPORT_PLUGIN(FormEditorPlugin)