changed items to shared ptrs

app/task/import/import.cpp

@@ -59,6 +59,11 @@ void ImportTask::Import(const QStringList &files, Folder *folder, QUndoCommand *
 {
   for (int i=0;i<files.size();i++) {
 
+    // Stop here if the Task has been cancelled
+    if (cancelled()) {
+      break;
+    }
+
     const QString& url = files.at(i);
 
     QFileInfo file_info(url);
@@ -75,7 +80,8 @@ void ImportTask::Import(const QStringList &files, Folder *folder, QUndoCommand *
       // Only proceed if the empty actually has files in it
       if (!entry_list.isEmpty()) {
         // Create a folder corresponding to the directory
-        Folder* f = new Folder();
+
+        ItemPtr f = std::make_shared<Folder>();
 
         f->set_name(file_info.fileName());
 
@@ -95,12 +101,12 @@ void ImportTask::Import(const QStringList &files, Folder *folder, QUndoCommand *
         }
 
         // Recursively follow this path
-        Import(full_urls, f, parent_command);
+        Import(full_urls, static_cast<Folder*>(f.get()), parent_command);
       }
 
     } else {
 
-      Footage* f = new Footage();
+      FootagePtr f = std::make_shared<Footage>();
 
       // FIXME: Is it possible for a file to go missing between the Import dialog and here?
       //        And what is the behavior/result of that?

app/task/probe/probe.cpp

@@ -24,7 +24,7 @@
 
 #include "decoder/probeserver.h"
 
-ProbeTask::ProbeTask(Footage *footage) :
+ProbeTask::ProbeTask(FootagePtr footage) :
   footage_(footage)
 {
   QString base_filename = QFileInfo(footage_->filename()).fileName();
@@ -34,7 +34,7 @@ ProbeTask::ProbeTask(Footage *footage) :
 
 bool ProbeTask::Action()
 {
-  olive::ProbeMedia(footage_);
+  olive::ProbeMedia(footage_.get());
 
   return true;
 }

app/task/probe/probe.h

@@ -38,12 +38,12 @@ class ProbeTask : public Task
 {
   Q_OBJECT
 public:
-  ProbeTask(Footage* footage);
+  ProbeTask(FootagePtr footage);
 
   virtual bool Action() override;
 
 private:
-  Footage* footage_;
+  FootagePtr footage_;
 };
 
 #endif // PROBE_H

app/task/task.cpp

@@ -23,7 +23,8 @@
 Task::Task() :
   status_(kWaiting),
   thread_(this),
-  text_(tr("Task"))
+  text_(tr("Task")),
+  cancelled_(false)
 {
   connect(&thread_, SIGNAL(finished()), this, SLOT(ThreadComplete()));
 }
@@ -55,6 +56,8 @@ bool Task::Start()
     }
   }
 
+  cancelled_ = false;
+
   set_status(kWorking);
 
   thread_.start();
@@ -90,6 +93,18 @@ void Task::AddDependency(Task *dependency)
   dependencies_.append(dependency);
 }
 
+void Task::Cancel()
+{
+  if (status_ != kWorking) {
+    return;
+  }
+
+  cancelled_ = true;
+
+  // FIXME: Should we limit the wait time?
+  thread_.wait();
+}
+
 void Task::set_error(const QString &s)
 {
   error_ = s;
@@ -100,6 +115,11 @@ void Task::set_text(const QString &s)
   text_ = s;
 }
 
+bool Task::cancelled()
+{
+  return cancelled_;
+}
+
 void Task::set_status(const Task::Status &status)
 {
   status_ = status;

app/task/task.h

@@ -141,6 +141,18 @@ public:
    */
   void AddDependency(Task* dependency);
 
+public slots:
+  /**
+   * @brief Cancel the Task
+   *
+   * Sends a signal to the Task to stop and waits for the Task to finish before returning. Tasks must be responsive to
+   * cancelling so that the main thread doesn't halt for too long.
+   *
+   * Cancel()'s function is fairly simple, it sets cancelled_ to TRUE and waits for the thread to return. It's the
+   * responsibility of the code in Action() to be able to respond quickly to cancelled_ changing.
+   */
+  void Cancel();
+
 protected:
   /**
    * @brief Set the error message
@@ -159,6 +171,11 @@ protected:
    */
   void set_text(const QString& s);
 
+  /**
+   * @brief Returns whether the thread has been explicitly cancelled or not
+   */
+  bool cancelled();
+
 signals:
   /**
    * @brief Signal emitted whenever the Task status changes
@@ -197,6 +214,8 @@ private:
 
   QList<Task*> dependencies_;
 
+  bool cancelled_;
+
 private slots:
   /**
    * @brief A slot when the inner thread completes either successfully or unsuccessfully