Flow view more or less works now. Some small tweaks are still coming.

candatagrid.cpp

@@ -9,6 +9,9 @@ CANDataGrid::CANDataGrid(QWidget *parent) :
     ui(new Ui::CANDataGrid)
 {
     ui->setupUi(this);
+
+    memset(data, 0, 8);
+    memset(refData, 0, 8);
 }
 
 CANDataGrid::~CANDataGrid()
@@ -19,6 +22,9 @@ CANDataGrid::~CANDataGrid()
 void CANDataGrid::paintEvent(QPaintEvent *event)
 {
     int x, y;
+    unsigned char prevByte, thisByte;
+    bool thisBit, prevBit;
+    QBrush blackBrush, whiteBrush, redBrush, greenBrush;
     QPainter painter(this);
 
     QRect viewport = painter.viewport();
@@ -29,6 +35,11 @@ void CANDataGrid::paintEvent(QPaintEvent *event)
     int xSector = xSpan / 10;
     int ySector = ySpan / 10;
 
+    blackBrush = QBrush(Qt::black);
+    whiteBrush = QBrush(Qt::white);
+    redBrush = QBrush(Qt::red);
+    greenBrush = QBrush(Qt::green);
+
     //the whole thing is broken up into 100 chunks which are allocated as such:
     //The entirety of the upper row is taken up by "BITS"
     //The next row down skips two columns and then has 7 6 5 4 3 2 1 0
@@ -58,12 +69,59 @@ void CANDataGrid::paintEvent(QPaintEvent *event)
     painter.drawText(viewport.left() + 10, viewport.top() + ySector * 7, "E");
     painter.drawText(viewport.left() + 10, viewport.top() + ySector * 8, "S");
 
+    //now, color the bitfield by seeing if a given bit is freshly set/unset in the new data
+    //compared to the old. Bits that are not set in either are white, bits set in both are black
+    //bits that used to be set but now are unset are red, bits that used to be unset but now are set
+    //are green
+
     for (y = 0; y < 8; y++)
     {
+        thisByte = data[y];
+        prevByte = refData[y];
         for (x = 0; x < 8; x++)
         {
-            painter.drawRect(viewport.left() + (x+2) * xSector, viewport.top() + (y+2) * ySector, xSector, ySector);
+            thisBit = false;
+            prevBit = false;
+            if ((thisByte & (1 << x)) == (1 << x)) thisBit = true;
+            if ((prevByte & (1 << x)) == (1 << x)) prevBit = true;
 
+            if (thisBit)
+            {
+                if (prevBit)
+                {
+                    painter.setBrush(blackBrush);
+                }
+                else
+                {
+                    painter.setBrush(greenBrush);
+                }
+            }
+            else
+            {
+                if (prevBit)
+                {
+                    painter.setBrush(redBrush);
+                }
+                else
+                {
+                    painter.setBrush(whiteBrush);
+                }
+            }
+
+            //painter.fillRect(viewport.left() + (x+2) * xSector, viewport.top() + (y+2) * ySector, xSector, ySector, redBrush);
+            painter.drawRect(viewport.left() + (x+2) * xSector, viewport.top() + (y+2) * ySector, xSector, ySector);
         }
-    }
+    }             
+}
+
+void CANDataGrid::setReference(unsigned char *newRef, bool bUpdate = true)
+{
+    memcpy(refData, newRef, 8);
+    if (bUpdate) this->update();
+}
+
+void CANDataGrid::updateData(unsigned char *newData, bool bUpdate = true)
+{
+    memcpy(data, newData, 8); //on a 64 bit processor this is probably optimized to a single instruction
+    if (bUpdate) this->update();
 }