From 66879df3494451c44b68b2094ed19b692377acdb Mon Sep 17 00:00:00 2001
From: Nav <nav@navnav.me>
Date: Sat, 30 Oct 2021 14:47:58 +0100
Subject: [PATCH] Improved the performance of resizing the hex viewer widget,
 by only recalculating the byte item positions when absolutely necessary.

---
 .../HexViewerWidget/ByteItemGraphicsScene.cpp | 23 ++++++++++++-------
 1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/src/Insight/UserInterfaces/InsightWindow/Widgets/TargetMemoryInspectionPane/HexViewerWidget/ByteItemGraphicsScene.cpp b/src/Insight/UserInterfaces/InsightWindow/Widgets/TargetMemoryInspectionPane/HexViewerWidget/ByteItemGraphicsScene.cpp
index cdca7e68..d3eef13b 100644
--- a/src/Insight/UserInterfaces/InsightWindow/Widgets/TargetMemoryInspectionPane/HexViewerWidget/ByteItemGraphicsScene.cpp
+++ b/src/Insight/UserInterfaces/InsightWindow/Widgets/TargetMemoryInspectionPane/HexViewerWidget/ByteItemGraphicsScene.cpp
@@ -66,9 +66,6 @@ void ByteItemGraphicsScene::updateValues(const Targets::TargetMemoryBuffer& buff
 }
 
 void ByteItemGraphicsScene::adjustByteWidgets() {
-    std::map<std::size_t, std::vector<ByteItem*>> byteWidgetsByRowIndex;
-    std::map<std::size_t, std::vector<ByteItem*>> byteWidgetsByColumnIndex;
-
     const auto margins = QMargins(10, 10, 10, 10);
     const auto width = std::max(600, static_cast<int>(this->parent->width()));
 
@@ -81,6 +78,21 @@ void ByteItemGraphicsScene::adjustByteWidgets() {
         std::ceil(static_cast<double>(this->byteWidgetsByAddress.size()) / static_cast<double>(rowCapacity))
     );
 
+    this->setSceneRect(
+        0,
+        0,
+        width,
+        (rowCount * byteWidgetHeight) + margins.top() + margins.bottom()
+    );
+
+    // Don't bother recalculating the byte item positions if the number of rows have not changed.
+    if (rowCount == this->byteWidgetsByRowIndex.size()) {
+        return;
+    }
+
+    std::map<std::size_t, std::vector<ByteItem*>> byteWidgetsByRowIndex;
+    std::map<std::size_t, std::vector<ByteItem*>> byteWidgetsByColumnIndex;
+
     for (auto& [address, byteWidget] : this->byteWidgetsByAddress) {
         const auto rowIndex = static_cast<std::size_t>(
             std::ceil(static_cast<double>(byteWidget->byteIndex + 1) / static_cast<double>(rowCapacity)) - 1
@@ -104,11 +116,6 @@ void ByteItemGraphicsScene::adjustByteWidgets() {
         byteWidget->update();
     }
 
-    const auto minHeight = (rowCount * byteWidgetHeight) + margins.top() + margins.bottom();
-//    this->setMinimumHeight(minHeight);
-    this->setSceneRect(0, 0, width, minHeight);
-//    this->parent->setMinimumHeight(minHeight);
-
     this->byteWidgetsByRowIndex = std::move(byteWidgetsByRowIndex);
     this->byteWidgetsByColumnIndex = std::move(byteWidgetsByColumnIndex);