ThreadWithQuasiModalProgressWindow 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...

Inherits Thread, and Timer.

Classes
class	Holder
	This class manages the lifetime of the ThreadWithQuasiModalProgressWindow. More...

Public Member Functions
AlertWindow *	getAlertWindow () const noexcept
	Returns the AlertWindow that is being used. More...
bool	runThread (int priority=5)
	Starts the thread and waits for it to finish. 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...
virtual void	threadComplete (bool userPressedCancel)
	This method is called (on the message thread) when the operation has finished. More...
	ThreadWithQuasiModalProgressWindow (const String &windowTitle, bool hasProgressBar, bool hasCancelButton, Holder *holder, int timeOutMsWhenCancelling=10000, const String &cancelButtonText=String(), Component *componentToCentreAround=nullptr)
	Creates the thread. More...
	~ThreadWithQuasiModalProgressWindow ()
	Destructor. 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'
            if (threadShouldExit())
                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

ThreadWithQuasiModalProgressWindow	(	const String &	windowTitle,
		bool	hasProgressBar,
		bool	hasCancelButton,
		Holder *	holder,
		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

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

~ThreadWithQuasiModalProgressWindow

(

)

Destructor.

Member Function Documentation

AlertWindow* getAlertWindow ( ) const

inlinenoexcept

Returns the AlertWindow that is being used.

bool 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

priority

the 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

void setProgress

(

double

newProgress

)

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

Parameters

newProgress

the progress, from 0.0 to 1.0

See also

setStatusMessage

void setStatusMessage

(

const String &

newStatusMessage

)

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

void 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.