From bertrand:

Better version of CPUMeter.C


git-svn-id: http://root.cern.ch/svn/root/trunk@20800 27541ba8-7e3a-0410-8455-c3a389f83636

tutorials/gui/CPUMeter.C

@@ -11,8 +11,8 @@ class TGShapedMain : public TGMainFrame {
 
 protected:
    TGSpeedo          *fSpeedo;          // analog meter
+   TTimer            *fTimer;           // update timer
    Int_t              fActInfo;         // actual information value
-   Bool_t             fRunning;         // kTRUE while updating infos
 
 public:
    TGShapedMain(const TGWindow *p, int w, int h);
@@ -21,11 +21,16 @@ public:
    void              CloseWindow();
    TGSpeedo         *GetSpeedo() const { return fSpeedo; }
    Int_t             GetActInfo() const { return fActInfo; }
-   Bool_t            IsRunning() const { return fRunning; }
    void              ToggleInfos();
 };
 
 
+// globals
+TGShapedMain *gMainWindow;
+TGSpeedo *gSpeedo;
+Float_t prev_load;
+Int_t old_memUsage;
+
 //______________________________________________________________________________
 TGShapedMain::TGShapedMain(const TGWindow *p, int w, int h) :
    TGMainFrame(p, w, h)
@@ -33,23 +38,26 @@ TGShapedMain::TGShapedMain(const TGWindow *p, int w, int h) :
    // Constructor.
 
    fActInfo = 1;
-   fRunning = kTRUE;
 
    fSpeedo = new TGSpeedo(this, 0.0, 100.0, "CPU", "[%]");
    fSpeedo->Connect("OdoClicked()", "TGShapedMain", this, "ToggleInfos()");
    fSpeedo->Connect("LedClicked()", "TGShapedMain", this, "CloseWindow()");
-   TGMainFrame::Connect("CloseWindow()", "TGShapedMain", this, "CloseWindow()");
+   Connect("CloseWindow()", "TGShapedMain", this, "CloseWindow()");
    AddFrame(fSpeedo, new TGLayoutHints(kLHintsCenterX | kLHintsCenterX, 0, 0, 0, 0));
    fSpeedo->SetDisplayText("Used RAM", "[MB]");
+   fTimer = new TTimer(100);
+   fTimer->SetCommand("Update()");
 
    MapSubwindows();
    MapWindow();
    // To avoid closing the window while TGSpeedo is drawing
    DontCallClose();
+   // To avoid closing the window while TGSpeedo is drawing
    Resize(GetDefaultSize());
    // Set fixed size
    SetWMSizeHints(GetDefaultWidth(), GetDefaultHeight(), GetDefaultWidth(), GetDefaultHeight(), 1, 1);
    SetWindowName("ROOT CPU Load Meter");
+   fTimer->TurnOn();   
 }
 
 //______________________________________________________________________________
@@ -81,10 +89,43 @@ void TGShapedMain::CloseWindow()
 {
    // Close Window.
 
-   // stop updating
-   fRunning = kFALSE;
-   // reset kDontCallClose bit to be able to really close the window
-   ResetBit(kDontCallClose);
+   if (fTimer)
+      fTimer->TurnOff();
+   delete fTimer;
+   delete fSpeedo;
+   delete this;
+}
+
+void Update()
+{
+   MemInfo_t memInfo;
+   CpuInfo_t cpuInfo;
+   Float_t act_load = 0.0;
+   Int_t i, memUsage = 0;
+
+   // Get CPU informations
+   gSystem->GetCpuInfo(&cpuInfo, 100);
+   // actual CPU load
+   act_load = cpuInfo.fTotal;
+   // Get Memory informations
+   gSystem->GetMemInfo(&memInfo);
+   // choose which value to display
+   if (gMainWindow->GetActInfo() == 0)
+      memUsage = memInfo.fMemTotal;
+   else if (gMainWindow->GetActInfo() == 1)
+      memUsage = memInfo.fMemUsed;
+   else if (gMainWindow->GetActInfo() == 2)
+      memUsage = memInfo.fMemFree;
+   // small threshold to avoid "trembling" needle
+   if (fabs(act_load-prev_load) > 0.9) {
+      gSpeedo->SetScaleValue(act_load, 10);
+      prev_load = act_load;
+   }
+   // update only if value has changed
+   if (memUsage != old_memUsage) {
+      gSpeedo->SetOdoValue(memUsage);
+      old_memUsage = memUsage;
+   }
 }
 
 //______________________________________________________________________________
@@ -92,55 +133,18 @@ void CPUMeter()
 {
    // Main application.
 
-   MemInfo_t memInfo;
-   CpuInfo_t cpuInfo;
-   Float_t act_load, prev_load = 0.0;
-   Int_t i, memUsage, old_memUsage = 0;
-
-   TGShapedMain *mainWindow = new TGShapedMain(0, 500, 200);
-   TGSpeedo *speedo = mainWindow->GetSpeedo();
+   gMainWindow = new TGShapedMain(0, 500, 200);
+   gSpeedo = gMainWindow->GetSpeedo();
 
    // set threshold values
-   speedo->SetThresholds(12.5, 50.0, 87.5);
+   gSpeedo->SetThresholds(12.5, 50.0, 87.5);
    // set threshold colors
-   speedo->SetThresholdColors(TGSpeedo::kGreen, TGSpeedo::kOrange, TGSpeedo::kRed);
+   gSpeedo->SetThresholdColors(TGSpeedo::kGreen, TGSpeedo::kOrange, TGSpeedo::kRed);
    // enable threshold
-   speedo->EnableThreshold();
-   speedo->SetScaleValue(0.0, 5);
+   gSpeedo->EnableThreshold();
+   gSpeedo->SetScaleValue(0.0, 5);
    // enable peak marker
-   speedo->EnablePeakMark();
-   // update the TGSpeedo widget
-   gSystem->GetCpuInfo(&cpuInfo);
-   gSystem->GetMemInfo(&memInfo);
-   gSystem->ProcessEvents();
-   while (mainWindow->IsRunning() && mainWindow->IsMapped()) {
-      // Get CPU informations
-      gSystem->GetCpuInfo(&cpuInfo, 100);
-      // actual CPU load
-      act_load = cpuInfo.fTotal;
-      // Get Memory informations
-      gSystem->GetMemInfo(&memInfo);
-      // choose which value to display
-      if (mainWindow->GetActInfo() == 0)
-         memUsage = memInfo.fMemTotal;
-      else if (mainWindow->GetActInfo() == 1)
-         memUsage = memInfo.fMemUsed;
-      else if (mainWindow->GetActInfo() == 2)
-         memUsage = memInfo.fMemFree;
-      // small threshold to avoid "trembling" needle
-      if (fabs(act_load-prev_load) > 0.9) {
-         speedo->SetScaleValue(act_load, 10);
-         prev_load = act_load;
-      }
-      // update only if value has changed
-      if (memUsage != old_memUsage) {
-         speedo->SetOdoValue(memUsage);
-         old_memUsage = memUsage;
-      }
-      // sleep a bit
-      gSystem->ProcessEvents();
-      gSystem->Sleep(250);
-   }
-   mainWindow->CloseWindow();
+   gSpeedo->EnablePeakMark();
+
 }