Filter Library

Camera

Interface Physics

CProgressDlg Class Reference
[Dialog Related]

#include <ProgressDlg.h>

List of all members.

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Detailed Description

The progress dialog is used to indicate the progress of computational intensive operations and to enable the user to stop the computation prematurely. See for example cross-correlation in the spatial domain.

Class CProgressDlg is used as follows.

• the filter class creates a CProgressDlg object and saves information about itself in it; the progress dialog sets-up a timer to update its progress bar
• the filter class creates a suspended worker thread to do the computation
• the filter class calls dlg.DoModal( hThread ) wich resumes the worker thread
• the worker thread sets the progress bar range and text variables
• the worker thread performs the computation and based on its progress, updates the dialog's progress bar position variable
• the timer lets the progress dialog periodically update its text and progress bar range and position
• finally the worker thread terminates the progress dialog by sending it a WM_CLOSE message (see CProgressDlg::Terminate() )
• WM_CLOSE activates the dialog's OnCancel() handler which stops the timer used to update the progress bar

The user may cancel the computation prematurely by pressing the Cancel-button on the progress dialog or by pressing the Esc-key. In this case the progress dialog's OnCancel() handler is called and the following happens.

• OnCancel() sets a flag to signal the computation to stop (dlg->StopRequested())
• OnCancel() waits for the worker thread to finish, unless it has not been resumed before
• OnCancel() stops the timer used to update the dialog's progress bar
• the worker thread calls CProgressDlg::Terminate() but in the case it may not and does not generate a WM_CLOSE message, because the dialog is closing already ( CProgressDlg::IsCanceling() )

Note 1: handling of the Esc-key press was not implemented in the original version.
Note 2: waiting for the worker thread was not implemented in the original version.

Class CProgressDlg uses a critical section (CCriticalSection) to guard access to the dialog text, and progress bar range and position from different threads.

For more information, see the implementation of class CScanFilterCrossCorrelate.

Definition at line 74 of file ProgressDlg.h.

Public Member Functions
Predicates
BOOL	IsResumed ()
	the thread has informed us that it has been resumed.
BOOL	IsCanceling ()
	Cancel-button or Escape-key pressed (window close message).
BOOL	StopRequested ()
	Cancel-button or Esc-key pressed; alias for IsCanceling().
Mutators
void	SetResumed ()
	set resumed flag.
void	SetRange (int nLower, int nUpper)
	set progress bar range; Note just store, OnTimer updates dialog.
void	SetPos (int nPos)
	set progress bar position; Note just store, OnTimer updates dialog.
void	SetText (LPCTSTR lpcsText)
	set progress dialog message text; Note just store, OnTimer updates dialog.
void	Terminate ()
	close the progress dialog window.
virtual int	DoModal (CWinThread *pTread=NULL)
	display dialog as a modal window.
Protected Member Functions
virtual void	DoDataExchange (CDataExchange *pDX)
	Dialog Data Exchange (DDX) / Dialog Data Validation (DDV) support.
virtual BOOL	OnInitDialog ()
	initialize the dialog
afx_msg void	OnCancel ()
	handle cancel message (button)
afx_msg void	OnClose ()
	handle close message (button, Esc)
afx_msg void	OnTimer (UINT nIDEvent)
	handle timer event
BOOL	ResumeComputationThread (CWinThread *pThread)
	resume the given thread.
Protected Attributes
CWinThread *	m_pThread
	the computation thread
SECProgressCtrl	m_wndProgress
	advanced progress bar from Rogue Wave Objective Toolkit
volatile BOOL	m_bInitialized
	dialog is initialized flag
volatile BOOL	m_bCancel
	Cancel-button or Esc-key pressed flag.
volatile BOOL	m_bResumed
	computation thread has been resumed flag
CString	m_csMessage
	progress dialog message text
volatile int	m_nLowerPosition
	progress bar lower position
volatile int	m_nUpperPosition
	progress bar upper position
volatile int	m_nCurrentPosition
	progress bar current position
Private Types
enum	{ IDD = IDD_PROGRESSDLG }
Private Attributes
CCriticalSection	m_criticalSection
	critical section guard.
Static Private Attributes
static const int	c_nTimerIDEvent
	our timer event.

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Member Function Documentation

void CProgressDlg::Terminate

(

)

Definition at line 148 of file ProgressDlg.cpp.

References IsCanceling(), and m_bInitialized.

Referenced by CScanFilterLowPass::ComputationThreadFunction(), CScanFilterHighPass::ComputationThreadFunction(), CScanFilterFFTInverse::ComputationThreadFunction(), CScanFilterFFT::ComputationThreadFunction(), CScanFilterCrossCorrelateF::ComputationThreadFunction(), CScanFilterAutoCorrelate::ComputationThreadFunction(), CScanFilterCrossCorrelate2::SpawnComputationThread(), and CScanFilterCrossCorrelate::SpawnComputationThread().

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

• ProgressDlg.h
• ProgressDlg.cpp

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