Add a scroll bar to the hex widget

src/CMakeLists.txt

@@ -155,6 +155,7 @@ set(SOURCES
     tools/basefind/BaseFindDialog.cpp
     tools/basefind/BaseFindSearchDialog.cpp
     tools/basefind/BaseFindResultsDialog.cpp
+    widgets/AddressRangeScrollBar.cpp
 )
 set(HEADER_FILES
     core/Cutter.h
@@ -319,6 +320,7 @@ set(HEADER_FILES
     tools/basefind/BaseFindDialog.h
     tools/basefind/BaseFindSearchDialog.h
     tools/basefind/BaseFindResultsDialog.h
+    widgets/AddressRangeScrollBar.h
 )
 set(UI_FILES
     dialogs/AboutDialog.ui
@@ -500,7 +502,7 @@ endif()
 
 target_link_libraries(Cutter PUBLIC ${RIZIN_TARGET})
 if(CUTTER_ENABLE_PYTHON)
-    if(CMAKE_VERSION VERSION_LESS "3.12.0") 
+    if(CMAKE_VERSION VERSION_LESS "3.12.0")
         # On windows some of the Python STABLE API functions are in seperate library
         # which isn't added by CMake.
         if (WIN32)

src/widgets/AddressRangeScrollBar.cpp

@@ -0,0 +1,177 @@
+#include "AddressRangeScrollBar.h"
+#include "Cutter.h"
+
+#include <QWheelEvent>
+
+#include <algorithm>
+#include <cstring>
+
+AddressRangeScrollBar::AddressRangeScrollBar(QWidget *parent) : QScrollBar(parent)
+{
+    setSingleStep(0);
+    connect(Core(), &CutterCore::refreshAll, this, &AddressRangeScrollBar::refreshRange);
+    connect(this, &AddressRangeScrollBar::actionTriggered, this, [this](int action) {
+        switch (action) {
+        // Due to the way the QScrollBar::actionTriggered signal works,
+        // setting the slider pos to its current value here
+        // prevents it from moving, allowing us to basically
+        // override behavior for specific actions
+        // See https://doc.qt.io/qt-6/qabstractslider.html#actionTriggered
+        // for more info.
+        case QAbstractSlider::SliderSingleStepAdd:
+            setSliderPosition(value());
+            if (value() == maximum())
+                return;
+            emit scrolled(-3);
+            return;
+        case QAbstractSlider::SliderSingleStepSub:
+            setSliderPosition(value());
+            if (value() == minimum())
+                return;
+            emit scrolled(3);
+            return;
+        default:
+            return;
+        }
+    });
+}
+
+void AddressRangeScrollBar::refreshRange()
+{
+    beginOffset = RVA_MAX;
+    endOffset = 0;
+    if (!Core()->currentlyEmulating && Core()->currentlyDebugging) {
+        QString currentlyOpenFile = Core()->getConfig("file.path");
+        QList<MemoryMapDescription> memoryMaps = Core()->getMemoryMap();
+        for (const MemoryMapDescription &map : memoryMaps) {
+            if (map.fileName == currentlyOpenFile) {
+                if (map.addrStart < beginOffset) {
+                    beginOffset = map.addrStart;
+                }
+                if (map.addrEnd > endOffset) {
+                    endOffset = map.addrEnd;
+                }
+            }
+        }
+    } else {
+        RzCoreLocked core(Core());
+        RzPVector *mapsPtr = rz_io_maps(core->io);
+        if (!mapsPtr) {
+            emit hideScrollBar();
+            return;
+        }
+        CutterPVector<RzIOMap> maps { mapsPtr };
+        for (const RzIOMap *const map : maps) {
+            // Skip the ESIL memory stack region
+            if (Core()->currentlyEmulating && std::strncmp(rz_str_get(map->name), "mem.", 4) == 0) {
+                continue;
+            }
+            ut64 b = rz_itv_begin(map->itv);
+            ut64 e = rz_itv_end(map->itv);
+            if (b < beginOffset) {
+                beginOffset = b;
+            }
+            if (e > endOffset) {
+                endOffset = e;
+            }
+        }
+    }
+    if (endOffset) {
+        --endOffset;
+    }
+    if (endOffset == 0) {
+        beginOffset = 0;
+    }
+    setMinimum(0);
+    // Increasing this value increases scroll bar accuracy for small files but
+    // decreases it for large files
+    // Sufficiently below 2^32 to avoid causing problems in calculations done by QScrollbar,
+    // otherwise as high as possible to maximize range in which address map 1:1 to scrollbar pos.
+    const int rangeMax = 512 * 1024 * 1024;
+    if (rangeSize() > rangeMax) {
+        setMaximum(rangeMax);
+    } else {
+        setMaximum(rangeSize());
+    }
+    if (rangeSize()) {
+        emit showScrollBar();
+        return;
+    }
+    emit hideScrollBar();
+    return;
+}
+
+void AddressRangeScrollBar::setPosition(RVA address)
+{
+    const QSignalBlocker blocker(this);
+    if (!maximum() || !rangeSize()) {
+        emit hideScrollBar();
+        return;
+    }
+    int scrollBarPos = 0;
+    if (address < beginOffset) {
+        setValue(scrollBarPos);
+        emit showScrollBar();
+        return;
+    }
+    if (address > endOffset) {
+        setValue(maximum());
+        emit showScrollBar();
+        return;
+    }
+    auto offset = address - beginOffset;
+    if ((RVA_MAX / maximum()) < rangeSize()) {
+        // Fallback formula for large files
+        uint64_t smallBox = rangeSize() / maximum();
+        uint64_t extra = rangeSize() % maximum();
+        auto bigBoxRange = (smallBox + 1) * extra;
+        if (offset < bigBoxRange) {
+            scrollBarPos = offset / (smallBox + 1);
+        } else {
+            scrollBarPos = extra + (offset - bigBoxRange) / smallBox;
+        }
+    } else {
+        scrollBarPos = (maximum() * offset) / rangeSize();
+    }
+    if (address != beginOffset && scrollBarPos == 0) {
+        scrollBarPos = 1;
+    }
+    setValue(scrollBarPos);
+    emit showScrollBar();
+    return;
+}
+
+RVA AddressRangeScrollBar::address()
+{
+    if (!maximum() || !rangeSize()) {
+        return beginOffset;
+    }
+    // Fallback formula for large files
+    if ((RVA_MAX / maximum()) < rangeSize()) {
+        return value() * (rangeSize() / maximum()) + std::min<RVA>(value(), rangeSize() % maximum())
+                + beginOffset;
+    }
+    return (value() * rangeSize()) / maximum() + beginOffset;
+}
+
+RVA AddressRangeScrollBar::rangeSize()
+{
+    return endOffset - beginOffset;
+}
+
+void AddressRangeScrollBar::wheelEvent(QWheelEvent *event)
+{
+    accumScrollWheelDeltaY += event->angleDelta().y();
+    // Delta is reported in 1/8 of a degree
+    // eg. 120 units * 1/8 = 15 degrees
+    // Typical scroll speed is 1 line per 5 degrees
+    const int lineDelta = 5 * 8;
+    if (accumScrollWheelDeltaY >= lineDelta || accumScrollWheelDeltaY <= -lineDelta) {
+        int lineCount = accumScrollWheelDeltaY / lineDelta;
+        accumScrollWheelDeltaY -= lineDelta * lineCount;
+        if ((lineCount < 0 && value() == maximum()) || (lineCount > 0 && value() == minimum())) {
+            return;
+        }
+        emit scrolled(lineCount);
+    }
+}

src/widgets/AddressRangeScrollBar.h

@@ -0,0 +1,30 @@
+#ifndef ADDRESS_RANGE_SCROLLBAR_H
+#define ADDRESS_RANGE_SCROLLBAR_H
+
+#include <QScrollBar>
+#include "CutterCommon.h"
+
+class AddressRangeScrollBar : public QScrollBar
+{
+    Q_OBJECT
+public:
+    AddressRangeScrollBar(QWidget *parent = nullptr);
+    void refreshRange();
+    void setPosition(RVA address);
+    RVA address();
+    RVA rangeSize();
+
+signals:
+    void hideScrollBar();
+    void showScrollBar();
+    void scrolled(int lines);
+
+protected:
+    void wheelEvent(QWheelEvent *event) override;
+
+private:
+    RVA beginOffset = 0, endOffset = RVA_INVALID;
+    int accumScrollWheelDeltaY = 0;
+};
+
+#endif // ADDRESS_RANGE_SCROLLBAR_H