Highlight in red changes in the Hexdump Widget (#1880)

* Highlight changes in the Hexdump Widget

src/widgets/HexWidget.cpp

@@ -124,6 +124,7 @@ HexWidget::HexWidget(QWidget *parent) :
     startAddress = 0ULL;
     cursor.address = 0ULL;
     data.reset(new MemoryData());
+    oldData.reset(new MemoryData());
 
     fetchData();
     updateCursorMeta();
@@ -206,6 +207,27 @@ void HexWidget::setItemGroupSize(int size)
     viewport()->update();
 }
 
+/**
+ * @brief Checks if Item at the address changed compared to the last read data.
+ * @param address Address of Item to be compared.
+ * @return True if Item is different, False if Item is equal or last read didn't contain the address.
+ * @see HexWidget#readItem
+ *
+ * Checks if current Item at the address changed compared to the last read data.
+ * It is assumed that the current read data buffer contains the address.
+ */
+bool HexWidget::isItemDifferentAt(uint64_t address) {
+    if (address >= oldData->minIndex() && address < oldData->maxIndex()) {
+        uint64_t itemOffset = address - startAddress;
+        QVariant curItem = readItem(itemOffset);
+        data.swap(oldData);
+        QVariant oldItem = readItem(itemOffset);
+        data.swap(oldData);
+        return (oldItem != curItem);
+    }
+    return false;
+}
+
 void HexWidget::updateCounts()
 {
     actionHexPairs->setEnabled(rowSizeBytes > 1 && itemByteLen == 1
@@ -335,6 +357,7 @@ void HexWidget::updateColors()
     printableColor = Config()->getColor("ai.write");
     defColor = Config()->getColor("btext");
     addrColor = Config()->getColor("func_var_addr");
+    diffColor = Config()->getColor("graph.diff.unmatch");
 
     updateCursorMeta();
     viewport()->update();
@@ -465,13 +488,13 @@ void HexWidget::wheelEvent(QWheelEvent *event)
         startAddress = 0;
     } else if (delta > 0 && data->maxIndex() < static_cast<uint64_t>(bytesPerScreen())) {
         startAddress = 0;
-    } else if (delta > 0
-               && (data->maxIndex() - startAddress) <= static_cast<uint64_t>(bytesPerScreen() + delta - 1)) {
-        startAddress = (data->maxIndex() - bytesPerScreen()) + 1;
     } else {
         startAddress += delta;
     }
     fetchData();
+    if ((data->maxIndex() - startAddress) <= static_cast<uint64_t>(bytesPerScreen() + delta - 1)) {
+        startAddress = (data->maxIndex() - bytesPerScreen()) + 1;
+    }
     if (cursor.address >= startAddress && cursor.address <= lastVisibleAddr()) {
         /* Don't enable cursor blinking if selection isn't empty */
         cursorEnabled = selection.isEmpty();
@@ -756,6 +779,9 @@ void HexWidget::drawItemArea(QPainter &painter)
                 if (selection.contains(itemAddr)  && !cursorOnAscii) {
                     itemColor = palette().highlightedText().color();
                 }
+                if (isItemDifferentAt(itemAddr)) {
+                    itemColor.setRgb(diffColor.rgb());
+                }
                 painter.setPen(itemColor);
                 painter.drawText(itemRect, Qt::AlignVCenter, itemString);
                 itemRect.translate(itemWidth(), 0);
@@ -789,8 +815,12 @@ void HexWidget::drawAsciiArea(QPainter &painter)
         charRect.moveLeft(asciiArea.left());
         for (int j = 0; j < itemRowByteLen() && address <= data->maxIndex(); ++j, ++address) {
             ascii = renderAscii(address - startAddress, &color);
-            if (selection.contains(address) && cursorOnAscii)
+            if (selection.contains(address) && cursorOnAscii) {
                 color = palette().highlightedText().color();
+            }
+            if (isItemDifferentAt(address)) {
+                color.setRgb(diffColor.rgb());
+            }
             painter.setPen(color);
             /* Dots look ugly. Use fillRect() instead of drawText(). */
             if (ascii == '.') {
@@ -985,10 +1015,6 @@ void HexWidget::setCursorAddr(BasicCursor addr, bool select)
         /* Align start address */
         addressValue -= (addressValue % itemRowByteLen());
 
-        if (addressValue > (data->maxIndex() - bytesPerScreen()) + 1) {
-            addressValue = (data->maxIndex() - bytesPerScreen()) + 1;
-        }
-
         /* FIXME: handling Page Up/Down */
         if (addressValue == startAddress + bytesPerScreen()) {
             startAddress += itemRowByteLen();
@@ -997,6 +1023,10 @@ void HexWidget::setCursorAddr(BasicCursor addr, bool select)
         }
 
         fetchData();
+
+        if (startAddress > (data->maxIndex() - bytesPerScreen()) + 1) {
+            startAddress = (data->maxIndex() - bytesPerScreen()) + 1;
+        }
     }
 
     updateCursorMeta();
@@ -1192,6 +1222,7 @@ QChar HexWidget::renderAscii(int offset, QColor *color)
 
 void HexWidget::fetchData()
 {
+    data.swap(oldData);
     data->fetch(startAddress, bytesPerScreen());
 }
 

src/widgets/HexWidget.h

@@ -75,6 +75,7 @@ public:
     virtual void fetch(uint64_t addr, int len) = 0;
     virtual const void *dataPtr(uint64_t addr) = 0;
     virtual uint64_t maxIndex() = 0;
+    virtual uint64_t minIndex() = 0;
 };
 
 class BufferData : public AbstractData
@@ -121,14 +122,20 @@ public:
     void fetch(uint64_t address, int length) override
     {
         // FIXME: reuse data if possible
-        uint64_t alignedAddr = address & ~(4096ULL - 1);
+        const uint64_t blockSize = 0x1000ULL;
+        uint64_t alignedAddr = address & ~(blockSize - 1);
         int offset = address - alignedAddr;
-        int len = (offset + length + (4096 - 1)) & ~(4096 - 1);
+        int len = (offset + length + (blockSize - 1)) & ~(blockSize - 1);
         m_firstBlockAddr = alignedAddr;
+        m_lastValidAddr = length ? alignedAddr + len - 1 : 0;
+        if (m_lastValidAddr < m_firstBlockAddr) {
+            m_lastValidAddr = -1;
+            len = m_lastValidAddr - m_firstBlockAddr + 1;
+        }
         m_blocks.clear();
         uint64_t addr = alignedAddr;
-        for (int i = 0; i < len / 4096; ++i, addr += 4096) {
-            m_blocks.append(Core()->ioRead(addr, 4096));
+        for (int i = 0; i < len / blockSize; ++i, addr += blockSize) {
+            m_blocks.append(Core()->ioRead(addr, blockSize));
         }
     }
 
@@ -142,12 +149,18 @@ public:
 
     virtual uint64_t maxIndex() override
     {
-        return UINT64_MAX;
+        return m_lastValidAddr;
+    }
+
+    virtual uint64_t minIndex() override
+    {
+        return m_firstBlockAddr;
     }
 
 private:
     QVector<QByteArray> m_blocks;
-    uint64_t m_firstBlockAddr;
+    uint64_t m_firstBlockAddr = 0;
+    uint64_t m_lastValidAddr = 0;
 };
 
 class HexSelection
@@ -298,6 +311,7 @@ private:
     void setCursorAddr(BasicCursor addr, bool select = false);
     void updateCursorMeta();
     void setCursorOnAscii(bool ascii);
+    bool isItemDifferentAt(uint64_t address);
     const QColor itemColor(uint8_t byte);
     QVariant readItem(int offset, QColor *color = nullptr);
     QString renderItem(int offset, QColor *color = nullptr);
@@ -446,6 +460,7 @@ private:
     QColor backgroundColor;
     QColor defColor;
     QColor addrColor;
+    QColor diffColor;
     QColor b0x00Color;
     QColor b0x7fColor;
     QColor b0xffColor;
@@ -469,6 +484,7 @@ private:
     QAction *actionCopyAddress;
     QAction *actionSelectRange;
 
+    std::unique_ptr<AbstractData> oldData;
     std::unique_ptr<AbstractData> data;
 };
 

src/widgets/HexdumpWidget.cpp

@@ -80,6 +80,9 @@ HexdumpWidget::HexdumpWidget(MainWindow *main, QAction *action) :
 
     connect(Config(), SIGNAL(fontsUpdated()), this, SLOT(fontsUpdated()));
     connect(Core(), &CutterCore::refreshAll, this, [this]() { refresh(); });
+    connect(Core(), &CutterCore::instructionChanged, this, [this]() { refresh(); });
+    connect(Core(), &CutterCore::stackChanged, this, [this]() { refresh(); });
+    connect(Core(), &CutterCore::registersChanged, this, [this]() { refresh(); });
 
     connect(seekable, &CutterSeekable::seekableSeekChanged, this, &HexdumpWidget::onSeekChanged);
     connect(ui->hexTextView, &HexWidget::positionChanged, this, [this](RVA addr) {