JUCE
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ThreadWithProgressWindow Class Reference

A thread that automatically pops up a modal dialog box with a progress bar and cancel button while it's busy running. More...

Inheritance diagram for ThreadWithProgressWindow:

Public Member Functions

 ThreadWithProgressWindow (const String &windowTitle, bool hasProgressBar, bool hasCancelButton, int timeOutMsWhenCancelling=10000, const String &cancelButtonText=String(), Component *componentToCentreAround=nullptr)
 Creates the thread. More...
 
 ~ThreadWithProgressWindow () override
 Destructor. More...
 
bool runThread (int priority=5)
 Starts the thread and waits for it to finish. More...
 
void launchThread (int priority=5)
 Starts the thread and returns. More...
 
void setProgress (double newProgress)
 The thread should call this periodically to update the position of the progress bar. More...
 
void setStatusMessage (const String &newStatusMessage)
 The thread can call this to change the message that's displayed in the dialog box. More...
 
AlertWindowgetAlertWindow () const noexcept
 Returns the AlertWindow that is being used. More...
 
virtual void threadComplete (bool userPressedCancel)
 This method is called (on the message thread) when the operation has finished. More...
 
- Public Member Functions inherited from Thread
 Thread (const String &threadName, size_t threadStackSize=0)
 Creates a thread. More...
 
virtual ~Thread ()
 Destructor. More...
 
virtual void run ()=0
 Must be implemented to perform the thread's actual code. More...
 
void startThread ()
 Starts the thread running. More...
 
void startThread (int priority)
 Starts the thread with a given priority. More...
 
bool stopThread (int timeOutMilliseconds)
 Attempts to stop the thread running. More...
 
bool isThreadRunning () const
 Returns true if the thread is currently active. More...
 
void signalThreadShouldExit ()
 Sets a flag to tell the thread it should stop. More...
 
bool threadShouldExit () const
 Checks whether the thread has been told to stop running. More...
 
bool waitForThreadToExit (int timeOutMilliseconds) const
 Waits for the thread to stop. More...
 
void addListener (Listener *)
 Add a listener to this thread which will receive a callback when signalThreadShouldExit was called on this thread. More...
 
void removeListener (Listener *)
 Removes a listener added with addListener. More...
 
bool setPriority (int priority)
 Changes the thread's priority. More...
 
void setAffinityMask (uint32 affinityMask)
 Sets the affinity mask for the thread. More...
 
bool wait (int timeOutMilliseconds) const
 Suspends the execution of this thread until either the specified timeout period has elapsed, or another thread calls the notify() method to wake it up. More...
 
void notify () const
 Wakes up the thread. More...
 
ThreadID getThreadId () const noexcept
 Returns the ID of this thread. More...
 
const StringgetThreadName () const noexcept
 Returns the name of the thread. More...
 

Additional Inherited Members

- Public Types inherited from Thread
enum  { realtimeAudioPriority = -1 }
 Special realtime audio thread priority. More...
 
using ThreadID = void *
 A value type used for thread IDs. More...
 
- Static Public Member Functions inherited from Thread
static void launch (std::function< void()> functionToRun)
 Invokes a lambda or function on its own thread. More...
 
static bool currentThreadShouldExit ()
 Checks whether the current thread has been told to stop running. More...
 
static bool setCurrentThreadPriority (int priority)
 Changes the priority of the caller thread. More...
 
static void JUCE_CALLTYPE setCurrentThreadAffinityMask (uint32 affinityMask)
 Changes the affinity mask for the caller thread. More...
 
static void JUCE_CALLTYPE sleep (int milliseconds)
 Suspends the execution of the current thread until the specified timeout period has elapsed (note that this may not be exact). More...
 
static void JUCE_CALLTYPE yield ()
 Yields the current thread's CPU time-slot and allows a new thread to run. More...
 
static ThreadID JUCE_CALLTYPE getCurrentThreadId ()
 Returns an id that identifies the caller thread. More...
 
static Thread *JUCE_CALLTYPE getCurrentThread ()
 Finds the thread object that is currently running. More...
 
static void JUCE_CALLTYPE setCurrentThreadName (const String &newThreadName)
 Changes the name of the caller thread. More...
 
static void initialiseJUCE (void *jniEnv, void *jContext)
 Initialises the JUCE subsystem for projects not created by the Projucer. More...
 

Detailed Description

A thread that automatically pops up a modal dialog box with a progress bar and cancel button while it's busy running.

These are handy for performing some sort of task while giving the user feedback about how long there is to go, etc.

E.g.

class MyTask : public ThreadWithProgressWindow
{
public:
MyTask() : ThreadWithProgressWindow ("busy...", true, true)
{
}
void run()
{
for (int i = 0; i < thingsToDo; ++i)
{
// must check this as often as possible, because this is
// how we know if the user's pressed 'cancel'
break;
// this will update the progress bar on the dialog box
setProgress (i / (double) thingsToDo);
// ... do the business here...
}
}
};
void doTheTask()
{
MyTask m;
if (m.runThread())
{
// thread finished normally..
}
else
{
// user pressed the cancel button..
}
}
See also
Thread, AlertWindow

Constructor & Destructor Documentation

◆ ThreadWithProgressWindow()

ThreadWithProgressWindow::ThreadWithProgressWindow ( const String windowTitle,
bool  hasProgressBar,
bool  hasCancelButton,
int  timeOutMsWhenCancelling = 10000,
const String cancelButtonText = String(),
Component componentToCentreAround = nullptr 
)

Creates the thread.

Initially, the dialog box won't be visible, it'll only appear when the runThread() method is called.

Parameters
windowTitlethe title to go at the top of the dialog box
hasProgressBarwhether the dialog box should have a progress bar (see setProgress() )
hasCancelButtonwhether the dialog box should have a cancel button
timeOutMsWhenCancellingwhen 'cancel' is pressed, this is how long to wait for the thread to stop before killing it forcibly (see Thread::stopThread() )
cancelButtonTextthe text that should be shown in the cancel button (if it has one). Leave this empty for the default "Cancel"
componentToCentreAroundif this is non-null, the window will be positioned so that it's centred around this component.

◆ ~ThreadWithProgressWindow()

ThreadWithProgressWindow::~ThreadWithProgressWindow ( )
override

Destructor.

Member Function Documentation

◆ runThread()

bool ThreadWithProgressWindow::runThread ( int  priority = 5)

Starts the thread and waits for it to finish.

This will start the thread, make the dialog box appear, and wait until either the thread finishes normally, or until the cancel button is pressed.

Before returning, the dialog box will be hidden.

Parameters
prioritythe priority to use when starting the thread - see Thread::startThread() for values
Returns
true if the thread finished normally; false if the user pressed cancel

◆ launchThread()

void ThreadWithProgressWindow::launchThread ( int  priority = 5)

Starts the thread and returns.

This will start the thread and make the dialog box appear in a modal state. When the thread finishes normally, or the cancel button is pressed, the window will be hidden and the threadComplete() method will be called.

Parameters
prioritythe priority to use when starting the thread - see Thread::startThread() for values

◆ setProgress()

void ThreadWithProgressWindow::setProgress ( double  newProgress)

The thread should call this periodically to update the position of the progress bar.

Parameters
newProgressthe progress, from 0.0 to 1.0
See also
setStatusMessage

◆ setStatusMessage()

void ThreadWithProgressWindow::setStatusMessage ( const String newStatusMessage)

The thread can call this to change the message that's displayed in the dialog box.

◆ getAlertWindow()

AlertWindow* ThreadWithProgressWindow::getAlertWindow ( ) const
noexcept

Returns the AlertWindow that is being used.

References JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR, and Timer::timerCallback().

◆ threadComplete()

virtual void ThreadWithProgressWindow::threadComplete ( bool  userPressedCancel)
virtual

This method is called (on the message thread) when the operation has finished.

You may choose to use this callback to delete the ThreadWithProgressWindow object.


The documentation for this class was generated from the following file: