VCL controls disappearing when a TProgressBar is being painted
I have a simple dialogue, which contains two TProgressBar controls and two TStaticText controls. The dialogue looks like this:
When I start painting the two progress bars, the two static text controls disappear (and reappear after the painting has finished).
The code doing the painting (probably irrelevant but here it is all the same)
void TForm1::UpdateActionProgress(unsigned progress){
static unsigned numPasses = 0;
const unsigned passWidth = frmProgressDlg->pbTotalProcessing->Max/numToProcess;
unsigned prevPos = frmProgressDlg->pbProcessing->Position;
int delta = progress-prevPos;
if(delta<0) {
delta=5;
numPasses++;
frmProgressDlg->pbTotalProcessing->Position = numPasses*passWidth;
}
frmProgressDlg->pbProcessing->Position = progress;
frmProgressDlg->pbTotalProcessing->Position += (delta/numToProcess);
if(progress>=100 && numToProcess==(numPasses+1))
frmProgressDlg->pbTotalProcessing->Position = 100;
//close the dialogue when finished
if(frmProgressDlg->pbTotalProcessing->Position>=100) {
frmProgressDlg->Close();
frmProgressDlg->pbTotalProcessing->Position = 0;
numPasses = 0;
}
}else{ //or show the dialogue if not already shown
if(!(frmProgressDlg->Visible))frmProgressDlg->Show();
}
UPDATE: Like I said in a comment, I'm not updating the GUI from the worker thread.
Basically, the method UpdateActionProgress is always called from the main thread in a while loop (in UpdateProgressFromThread).
So, the code calling UpdateActionProgress is like this:
void TForm1::DrawFilteredWave(EFilterType eFilterType, EWindow eWnd,
unsigned cutoffFreqLo, unsigned cutoffFreqHi, unsigned filterLength,
vector<PFILTERBAND_INFO> &vBandInfo, bool invert ){
....
pDigitalFilter->UseBackgroundThread(true);
pDigitalFilter->ApplyFilter(pSelData, numSamples);
//if using a background thread, wait till it has finished executing
UpdateProgressFromThread(pDigitalFilter);
....
}
void TForm1::UpdateProgressFromThread(void *pp){
DigitalFilter *p = (DigitalFilter*)pp;
if(p->IsBackgroundThread()) {
while(!(p->IsBackgroundThreadFinished())) {
unsigned progress = p->GetProgressValue();
if(progress>0) {
UpdateActionProgress(progress);
}
}
}
}
Still, I'm updating the GUI using an asynchronous queue (a very simple queue) and I'm not using using TThread::Synchronize because it's broken (see this). I tried using Synchronize but the app would hang on a call to Synchronize.
I will try to reproduce this using the least amount of code possible, but at the moment, this is all I have.
c++ vcl c++builder-6
edited Nov 23 at 23:23
Remy Lebeau
330k18251442
asked Nov 22 at 18:21
dsp_user
1,23521015
|
show 6 more comments
I have a simple dialogue, which contains two TProgressBar controls and two TStaticText controls. The dialogue looks like this:
When I start painting the two progress bars, the two static text controls disappear (and reappear after the painting has finished).
The code doing the painting (probably irrelevant but here it is all the same)
void TForm1::UpdateActionProgress(unsigned progress){
static unsigned numPasses = 0;
const unsigned passWidth = frmProgressDlg->pbTotalProcessing->Max/numToProcess;
unsigned prevPos = frmProgressDlg->pbProcessing->Position;
int delta = progress-prevPos;
if(delta<0) {
delta=5;
numPasses++;
frmProgressDlg->pbTotalProcessing->Position = numPasses*passWidth;
}
frmProgressDlg->pbProcessing->Position = progress;
frmProgressDlg->pbTotalProcessing->Position += (delta/numToProcess);
if(progress>=100 && numToProcess==(numPasses+1))
frmProgressDlg->pbTotalProcessing->Position = 100;
//close the dialogue when finished
if(frmProgressDlg->pbTotalProcessing->Position>=100) {
frmProgressDlg->Close();
frmProgressDlg->pbTotalProcessing->Position = 0;
numPasses = 0;
}
}else{ //or show the dialogue if not already shown
if(!(frmProgressDlg->Visible))frmProgressDlg->Show();
}
UPDATE: Like I said in a comment, I'm not updating the GUI from the worker thread.
Basically, the method UpdateActionProgress is always called from the main thread in a while loop (in UpdateProgressFromThread).
So, the code calling UpdateActionProgress is like this:
void TForm1::DrawFilteredWave(EFilterType eFilterType, EWindow eWnd,
unsigned cutoffFreqLo, unsigned cutoffFreqHi, unsigned filterLength,
vector<PFILTERBAND_INFO> &vBandInfo, bool invert ){
....
pDigitalFilter->UseBackgroundThread(true);
pDigitalFilter->ApplyFilter(pSelData, numSamples);
//if using a background thread, wait till it has finished executing
UpdateProgressFromThread(pDigitalFilter);
....
}
void TForm1::UpdateProgressFromThread(void *pp){
DigitalFilter *p = (DigitalFilter*)pp;
if(p->IsBackgroundThread()) {
while(!(p->IsBackgroundThreadFinished())) {
unsigned progress = p->GetProgressValue();
if(progress>0) {
UpdateActionProgress(progress);
}
}
}
}
Still, I'm updating the GUI using an asynchronous queue (a very simple queue) and I'm not using using TThread::Synchronize because it's broken (see this). I tried using Synchronize but the app would hang on a call to Synchronize.
I will try to reproduce this using the least amount of code possible, but at the moment, this is all I have.
c++ vcl c++builder-6
edited Nov 23 at 23:23
Remy Lebeau
330k18251442
asked Nov 22 at 18:21
dsp_user
1,23521015
Please provide a Minimal, Complete, and Verifiable example demonstrating the problem in action. Where isUpdateActionProgress()being called from? What you describe sounds like it is being called in a loop that blocks the main message loop from processing new UI messages until the loop ends.
– Remy Lebeau
Nov 22 at 22:20
@Remy Lebeau, the whole code is quite lengthy and I'm currently using threads and updating from a worker thread. Still, this didn't work even when I used only a single thread (the main thread). That's why I didn't post the whole thing. I assumed that someone had a similar problem. I can post the whole thing but it's going to take a while.
– dsp_user
Nov 22 at 22:36
Again, please provide a Minimal, Complete, and Verifiable example (emphasis on Minimal). And I hope you are not callingUpdateActionProgress()directly in your worker threads. The VCL is not thread-safe, UI updates must to be synchronized with the main UI thread. Drawing issues are the least of your worries if you don't do that properly.
– Remy Lebeau
Nov 22 at 22:42
I've updated my answer, for now.
– dsp_user
Nov 22 at 23:03
1
That while() loop in UpdateProgressFromThread() is fatal, it prevents the UI thread from dispatching anything else. Like the WM_PAINT notifications of those static controls. You'll have to rethink this, maybe a timer.
– Hans Passant
Nov 23 at 0:17
|
show 6 more comments
I have a simple dialogue, which contains two TProgressBar controls and two TStaticText controls. The dialogue looks like this:
When I start painting the two progress bars, the two static text controls disappear (and reappear after the painting has finished).
The code doing the painting (probably irrelevant but here it is all the same)
void TForm1::UpdateActionProgress(unsigned progress){
static unsigned numPasses = 0;
const unsigned passWidth = frmProgressDlg->pbTotalProcessing->Max/numToProcess;
unsigned prevPos = frmProgressDlg->pbProcessing->Position;
int delta = progress-prevPos;
if(delta<0) {
delta=5;
numPasses++;
frmProgressDlg->pbTotalProcessing->Position = numPasses*passWidth;
}
frmProgressDlg->pbProcessing->Position = progress;
frmProgressDlg->pbTotalProcessing->Position += (delta/numToProcess);
if(progress>=100 && numToProcess==(numPasses+1))
frmProgressDlg->pbTotalProcessing->Position = 100;
//close the dialogue when finished
if(frmProgressDlg->pbTotalProcessing->Position>=100) {
frmProgressDlg->Close();
frmProgressDlg->pbTotalProcessing->Position = 0;
numPasses = 0;
}
}else{ //or show the dialogue if not already shown
if(!(frmProgressDlg->Visible))frmProgressDlg->Show();
}
UPDATE: Like I said in a comment, I'm not updating the GUI from the worker thread.
Basically, the method UpdateActionProgress is always called from the main thread in a while loop (in UpdateProgressFromThread).
So, the code calling UpdateActionProgress is like this:
void TForm1::DrawFilteredWave(EFilterType eFilterType, EWindow eWnd,
unsigned cutoffFreqLo, unsigned cutoffFreqHi, unsigned filterLength,
vector<PFILTERBAND_INFO> &vBandInfo, bool invert ){
....
pDigitalFilter->UseBackgroundThread(true);
pDigitalFilter->ApplyFilter(pSelData, numSamples);
//if using a background thread, wait till it has finished executing
UpdateProgressFromThread(pDigitalFilter);
....
}
void TForm1::UpdateProgressFromThread(void *pp){
DigitalFilter *p = (DigitalFilter*)pp;
if(p->IsBackgroundThread()) {
while(!(p->IsBackgroundThreadFinished())) {
unsigned progress = p->GetProgressValue();
if(progress>0) {
UpdateActionProgress(progress);
}
}
}
}
Still, I'm updating the GUI using an asynchronous queue (a very simple queue) and I'm not using using TThread::Synchronize because it's broken (see this). I tried using Synchronize but the app would hang on a call to Synchronize.
I will try to reproduce this using the least amount of code possible, but at the moment, this is all I have.
c++ vcl c++builder-6
edited Nov 23 at 23:23
Remy Lebeau
330k18251442
asked Nov 22 at 18:21
dsp_user
1,23521015
I have a simple dialogue, which contains two TProgressBar controls and two TStaticText controls. The dialogue looks like this:
When I start painting the two progress bars, the two static text controls disappear (and reappear after the painting has finished).
The code doing the painting (probably irrelevant but here it is all the same)
void TForm1::UpdateActionProgress(unsigned progress){
static unsigned numPasses = 0;
const unsigned passWidth = frmProgressDlg->pbTotalProcessing->Max/numToProcess;
unsigned prevPos = frmProgressDlg->pbProcessing->Position;
int delta = progress-prevPos;
if(delta<0) {
delta=5;
numPasses++;
frmProgressDlg->pbTotalProcessing->Position = numPasses*passWidth;
}
frmProgressDlg->pbProcessing->Position = progress;
frmProgressDlg->pbTotalProcessing->Position += (delta/numToProcess);
if(progress>=100 && numToProcess==(numPasses+1))
frmProgressDlg->pbTotalProcessing->Position = 100;
//close the dialogue when finished
if(frmProgressDlg->pbTotalProcessing->Position>=100) {
frmProgressDlg->Close();
frmProgressDlg->pbTotalProcessing->Position = 0;
numPasses = 0;
}
}else{ //or show the dialogue if not already shown
if(!(frmProgressDlg->Visible))frmProgressDlg->Show();
}
UPDATE: Like I said in a comment, I'm not updating the GUI from the worker thread.
Basically, the method UpdateActionProgress is always called from the main thread in a while loop (in UpdateProgressFromThread).
So, the code calling UpdateActionProgress is like this:
void TForm1::DrawFilteredWave(EFilterType eFilterType, EWindow eWnd,
unsigned cutoffFreqLo, unsigned cutoffFreqHi, unsigned filterLength,
vector<PFILTERBAND_INFO> &vBandInfo, bool invert ){
....
pDigitalFilter->UseBackgroundThread(true);
pDigitalFilter->ApplyFilter(pSelData, numSamples);
//if using a background thread, wait till it has finished executing
UpdateProgressFromThread(pDigitalFilter);
....
}
void TForm1::UpdateProgressFromThread(void *pp){
DigitalFilter *p = (DigitalFilter*)pp;
if(p->IsBackgroundThread()) {
while(!(p->IsBackgroundThreadFinished())) {
unsigned progress = p->GetProgressValue();
if(progress>0) {
UpdateActionProgress(progress);
}
}
}
}
Still, I'm updating the GUI using an asynchronous queue (a very simple queue) and I'm not using using TThread::Synchronize because it's broken (see this). I tried using Synchronize but the app would hang on a call to Synchronize.
I will try to reproduce this using the least amount of code possible, but at the moment, this is all I have.
c++ vcl c++builder-6
c++ vcl c++builder-6
edited Nov 23 at 23:23
Remy Lebeau
330k18251442
asked Nov 22 at 18:21
dsp_user
1,23521015
edited Nov 23 at 23:23
Remy Lebeau
330k18251442
asked Nov 22 at 18:21
dsp_user
1,23521015
edited Nov 23 at 23:23
Remy Lebeau
330k18251442
edited Nov 23 at 23:23
Remy Lebeau
330k18251442
edited Nov 23 at 23:23
Remy Lebeau
330k18251442
330k18251442
asked Nov 22 at 18:21
dsp_user
1,23521015
asked Nov 22 at 18:21
dsp_user
1,23521015
asked Nov 22 at 18:21
dsp_user
1,23521015
1,23521015
Please provide a Minimal, Complete, and Verifiable example demonstrating the problem in action. Where isUpdateActionProgress()being called from? What you describe sounds like it is being called in a loop that blocks the main message loop from processing new UI messages until the loop ends.
– Remy Lebeau
Nov 22 at 22:20
@Remy Lebeau, the whole code is quite lengthy and I'm currently using threads and updating from a worker thread. Still, this didn't work even when I used only a single thread (the main thread). That's why I didn't post the whole thing. I assumed that someone had a similar problem. I can post the whole thing but it's going to take a while.
– dsp_user
Nov 22 at 22:36
Again, please provide a Minimal, Complete, and Verifiable example (emphasis on Minimal). And I hope you are not callingUpdateActionProgress()directly in your worker threads. The VCL is not thread-safe, UI updates must to be synchronized with the main UI thread. Drawing issues are the least of your worries if you don't do that properly.
– Remy Lebeau
Nov 22 at 22:42
I've updated my answer, for now.
– dsp_user
Nov 22 at 23:03
1
That while() loop in UpdateProgressFromThread() is fatal, it prevents the UI thread from dispatching anything else. Like the WM_PAINT notifications of those static controls. You'll have to rethink this, maybe a timer.
– Hans Passant
Nov 23 at 0:17
|
show 6 more comments
Please provide a Minimal, Complete, and Verifiable example demonstrating the problem in action. Where isUpdateActionProgress()being called from? What you describe sounds like it is being called in a loop that blocks the main message loop from processing new UI messages until the loop ends.
– Remy Lebeau
Nov 22 at 22:20
@Remy Lebeau, the whole code is quite lengthy and I'm currently using threads and updating from a worker thread. Still, this didn't work even when I used only a single thread (the main thread). That's why I didn't post the whole thing. I assumed that someone had a similar problem. I can post the whole thing but it's going to take a while.
– dsp_user
Nov 22 at 22:36
Again, please provide a Minimal, Complete, and Verifiable example (emphasis on Minimal). And I hope you are not callingUpdateActionProgress()directly in your worker threads. The VCL is not thread-safe, UI updates must to be synchronized with the main UI thread. Drawing issues are the least of your worries if you don't do that properly.
– Remy Lebeau
Nov 22 at 22:42
I've updated my answer, for now.
– dsp_user
Nov 22 at 23:03
1
That while() loop in UpdateProgressFromThread() is fatal, it prevents the UI thread from dispatching anything else. Like the WM_PAINT notifications of those static controls. You'll have to rethink this, maybe a timer.
– Hans Passant
Nov 23 at 0:17
Please provide a Minimal, Complete, and Verifiable example demonstrating the problem in action. Where is
UpdateActionProgress() being called from? What you describe sounds like it is being called in a loop that blocks the main message loop from processing new UI messages until the loop ends.– Remy Lebeau
Nov 22 at 22:20
Please provide a Minimal, Complete, and Verifiable example demonstrating the problem in action. Where is
UpdateActionProgress() being called from? What you describe sounds like it is being called in a loop that blocks the main message loop from processing new UI messages until the loop ends.– Remy Lebeau
Nov 22 at 22:20
@Remy Lebeau, the whole code is quite lengthy and I'm currently using threads and updating from a worker thread. Still, this didn't work even when I used only a single thread (the main thread). That's why I didn't post the whole thing. I assumed that someone had a similar problem. I can post the whole thing but it's going to take a while.
– dsp_user
Nov 22 at 22:36
@Remy Lebeau, the whole code is quite lengthy and I'm currently using threads and updating from a worker thread. Still, this didn't work even when I used only a single thread (the main thread). That's why I didn't post the whole thing. I assumed that someone had a similar problem. I can post the whole thing but it's going to take a while.
– dsp_user
Nov 22 at 22:36
Again, please provide a Minimal, Complete, and Verifiable example (emphasis on Minimal). And I hope you are not calling
UpdateActionProgress() directly in your worker threads. The VCL is not thread-safe, UI updates must to be synchronized with the main UI thread. Drawing issues are the least of your worries if you don't do that properly.– Remy Lebeau
Nov 22 at 22:42
Again, please provide a Minimal, Complete, and Verifiable example (emphasis on Minimal). And I hope you are not calling
UpdateActionProgress() directly in your worker threads. The VCL is not thread-safe, UI updates must to be synchronized with the main UI thread. Drawing issues are the least of your worries if you don't do that properly.– Remy Lebeau
Nov 22 at 22:42
I've updated my answer, for now.
– dsp_user
Nov 22 at 23:03
I've updated my answer, for now.
– dsp_user
Nov 22 at 23:03
1
1
That while() loop in UpdateProgressFromThread() is fatal, it prevents the UI thread from dispatching anything else. Like the WM_PAINT notifications of those static controls. You'll have to rethink this, maybe a timer.
– Hans Passant
Nov 23 at 0:17
That while() loop in UpdateProgressFromThread() is fatal, it prevents the UI thread from dispatching anything else. Like the WM_PAINT notifications of those static controls. You'll have to rethink this, maybe a timer.
– Hans Passant
Nov 23 at 0:17
|
show 6 more comments
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Please provide a Minimal, Complete, and Verifiable example demonstrating the problem in action. Where is
UpdateActionProgress()being called from? What you describe sounds like it is being called in a loop that blocks the main message loop from processing new UI messages until the loop ends.– Remy Lebeau
Nov 22 at 22:20
@Remy Lebeau, the whole code is quite lengthy and I'm currently using threads and updating from a worker thread. Still, this didn't work even when I used only a single thread (the main thread). That's why I didn't post the whole thing. I assumed that someone had a similar problem. I can post the whole thing but it's going to take a while.
– dsp_user
Nov 22 at 22:36
Again, please provide a Minimal, Complete, and Verifiable example (emphasis on Minimal). And I hope you are not calling
UpdateActionProgress()directly in your worker threads. The VCL is not thread-safe, UI updates must to be synchronized with the main UI thread. Drawing issues are the least of your worries if you don't do that properly.– Remy Lebeau
Nov 22 at 22:42
I've updated my answer, for now.
– dsp_user
Nov 22 at 23:03
1
That while() loop in UpdateProgressFromThread() is fatal, it prevents the UI thread from dispatching anything else. Like the WM_PAINT notifications of those static controls. You'll have to rethink this, maybe a timer.
– Hans Passant
Nov 23 at 0:17