DiffEditorController: Make it possible to setup task tree

Instead of reloader function. Use task tree for ShowController.
Make diff processing a part of task tree.

Change-Id: I732d0a14eaf8de7ce0d1be891fb4700b22ea24b7
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Orgad Shaneh <orgads@gmail.com>

src/plugins/diffeditor/diffeditorcontroller.cpp

@@ -8,6 +8,7 @@
 #include <coreplugin/editormanager/editormanager.h>
 #include <coreplugin/editormanager/ieditor.h>
 #include <coreplugin/icore.h>
+#include <coreplugin/progressmanager/taskprogress.h>
 
 #include <utils/qtcassert.h>
 
@@ -122,12 +123,22 @@ void DiffEditorController::requestReload()
 {
     m_isReloading = true;
     m_document->beginReload();
-    QTC_ASSERT(m_reloader, reloadFinished(false); return);
-    m_reloader();
+    if (m_reloader) {
+        m_reloader();
+        return;
+    }
+    m_taskTree.reset(new TaskTree(reloadRecipe()));
+    connect(m_taskTree.get(), &TaskTree::done, this, [this] { reloadFinished(true); });
+    connect(m_taskTree.get(), &TaskTree::errorOccurred, this, [this] { reloadFinished(false); });
+    auto progress = new TaskProgress(m_taskTree.get());
+    progress->setDisplayName(displayName());
+    m_taskTree->start();
 }
 
 void DiffEditorController::reloadFinished(bool success)
 {
+    if (m_taskTree)
+        m_taskTree.release()->deleteLater();
     m_document->endReload(success);
     m_isReloading = false;
 }

src/plugins/diffeditor/diffeditorcontroller.h

@@ -7,6 +7,7 @@
 #include "diffutils.h"
 
 #include <utils/filepath.h>
+#include <utils/tasktree.h>
 
 #include <QObject>
 
@@ -57,6 +58,9 @@ signals:
                                const ChunkSelection &selection);
 
 protected:
+    void setDisplayName(const QString &name) { m_displayName = name; }
+    QString displayName() const { return m_displayName; }
+
     // reloadFinished() should be called inside the reloader (for synchronous reload)
     // or later (for asynchronous reload)
     void setReloader(const std::function<void ()> &reloader);
@@ -72,7 +76,10 @@ protected:
 private:
     Internal::DiffEditorDocument *const m_document;
     bool m_isReloading = false;
+    QString m_displayName;
     std::function<void()> m_reloader;
+    std::unique_ptr<Utils::TaskTree> m_taskTree;
+    virtual Utils::Tasking::Group reloadRecipe() { return {}; } // TODO: make pure abstract
 
     friend class Internal::DiffEditorDocument;
 };