impr: Return early to remove nested code (#1253)

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### Problem description
<!-- Describe the bug that you fixed/feature request that you
implemented, or link to an existing issue describing it -->
This will simplify the codebase in the pattern drawer. It returns early
on conditional statements and reduces the amount of nested code making
it easier to read and track while developing.

plugins/builtin/source/ui/pattern_drawer.cpp

@@ -109,9 +109,12 @@ namespace hex::plugin::builtin::ui {
         }
 
         void drawOffsetColumn(const pl::ptrn::Pattern& pattern) {
-            if (auto *bitfieldMember = dynamic_cast<pl::ptrn::PatternBitfieldMember const*>(&pattern); bitfieldMember != nullptr && bitfieldMember->getParentBitfield() != nullptr)
+            auto *bitfieldMember = dynamic_cast<pl::ptrn::PatternBitfieldMember const*>(&pattern); 
+            if (bitfieldMember != nullptr && bitfieldMember->getParentBitfield() != nullptr) {
                 drawOffsetColumnForBitfieldMember(*bitfieldMember);
-            else {
+                return;
+            }
+            
             if (pattern.isPatternLocal()) {
                 ImGui::TextFormatted("[{}]", "hex.builtin.pattern_drawer.local"_lang);
             } else {
@@ -128,7 +131,6 @@ namespace hex::plugin::builtin::ui {
 
             ImGui::TableNextColumn();
         }
-        }
 
         inline void drawSizeColumnForBitfieldMember(const pl::ptrn::PatternBitfieldMember &pattern) {
             if (pattern.getBitSize() == 1)
@@ -155,7 +157,10 @@ namespace hex::plugin::builtin::ui {
         std::vector<std::string> parseRValueFilter(const std::string &filter) {
             std::vector<std::string> result;
 
-            if (!filter.empty()) {
+            if (filter.empty()) {
+                return result;
+            }
+
             result.emplace_back();
             for (char c : filter) {
                 if (c == '.')
@@ -167,7 +172,6 @@ namespace hex::plugin::builtin::ui {
                     result.back() += c;
                 }
             }
-            }
 
             return result;
         }
@@ -203,7 +207,11 @@ namespace hex::plugin::builtin::ui {
     }
 
     void PatternDrawer::drawFavoriteColumn(const pl::ptrn::Pattern& pattern) {
-        if (this->m_showFavoriteStars) {
+        if (!this->m_showFavoriteStars) {
+            ImGui::TableNextColumn();
+            return;
+        }
+
         ImGui::PushStyleVar(ImGuiStyleVar_FramePadding, ImVec2(0, 0));
 
         if (this->m_favorites.contains(this->m_currPatternPath)) {
@@ -218,7 +226,6 @@ namespace hex::plugin::builtin::ui {
         }
 
         ImGui::PopStyleVar();
-        }
 
         ImGui::TableNextColumn();
     }
@@ -305,7 +312,7 @@ namespace hex::plugin::builtin::ui {
             ImGui::Unindent();
             return false;
         }
-        else {
+
         return highlightWhenSelected(pattern, [&]{
             switch (this->m_treeStyle) {
                 using enum TreeStyle;
@@ -319,7 +326,6 @@ namespace hex::plugin::builtin::ui {
             }
         });
     }
-    }
 
     void PatternDrawer::makeSelectable(const pl::ptrn::Pattern &pattern) {
         ImGui::PushID(static_cast<int>(pattern.getOffset()));
@@ -389,7 +395,11 @@ namespace hex::plugin::builtin::ui {
         ImGui::TextFormattedColored(ImColor(0xFF9BC64D), "bits");
         ImGui::TableNextColumn();
 
-        if (this->isEditingPattern(pattern)) {
+        if (!this->isEditingPattern(pattern)) {
+            drawValueColumn(pattern);
+            return;
+        }
+
         ImGui::PushStyleVar(ImGuiStyleVar_FramePadding, ImVec2(0, 0));
         ImGui::PushItemWidth(ImGui::GetContentRegionAvail().x);
 
@@ -423,9 +433,6 @@ namespace hex::plugin::builtin::ui {
 
         ImGui::PopItemWidth();
         ImGui::PopStyleVar();
-        } else {
-            drawValueColumn(pattern);
-        }
     }
 
     void PatternDrawer::visit(pl::ptrn::PatternBitfieldArray& pattern) {
@@ -455,7 +462,10 @@ namespace hex::plugin::builtin::ui {
             drawValueColumn(pattern);
         }
 
-        if (open) {
+        if (!open) {
+            return;
+        }
+
         int id = 1;
         pattern.forEachEntry(0, pattern.getEntryCount(), [&] (u64, auto *field) {
             ImGui::PushID(id);
@@ -467,12 +477,15 @@ namespace hex::plugin::builtin::ui {
 
         closeTreeNode(pattern.isInlined());
     }
-    }
 
     void PatternDrawer::visit(pl::ptrn::PatternBoolean& pattern) {
         createDefaultEntry(pattern);
 
-        if (this->isEditingPattern(pattern)) {
+        if (!this->isEditingPattern(pattern)) {
+            drawValueColumn(pattern);
+            return;
+        }
+
         ImGui::PushStyleVar(ImGuiStyleVar_FramePadding, ImVec2(0, 0));
         ImGui::PushItemWidth(ImGui::GetContentRegionAvail().x);
 
@@ -483,15 +496,16 @@ namespace hex::plugin::builtin::ui {
 
         ImGui::PopItemWidth();
         ImGui::PopStyleVar();
-        } else {
-            drawValueColumn(pattern);
-        }
     }
 
     void PatternDrawer::visit(pl::ptrn::PatternCharacter& pattern) {
         createDefaultEntry(pattern);
 
-        if (this->isEditingPattern(pattern)) {
+        if (!this->isEditingPattern(pattern)) {
+            drawValueColumn(pattern);
+            return;
+        }
+            
         ImGui::PushStyleVar(ImGuiStyleVar_FramePadding, ImVec2(0, 0));
         ImGui::PushItemWidth(ImGui::GetContentRegionAvail().x);
         auto value = hex::encodeByteString(pattern.getBytes());
@@ -506,9 +520,6 @@ namespace hex::plugin::builtin::ui {
         }
         ImGui::PopItemWidth();
         ImGui::PopStyleVar();
-        } else {
-            drawValueColumn(pattern);
-        }
     }
 
     void PatternDrawer::visit(pl::ptrn::PatternEnum& pattern) {
@@ -524,7 +535,11 @@ namespace hex::plugin::builtin::ui {
         drawSizeColumn(pattern);
         drawTypenameColumn(pattern, "enum");
 
-        if (this->isEditingPattern(pattern)) {
+        if (!this->isEditingPattern(pattern)) {
+            drawValueColumn(pattern);
+            return;
+        }
+    
         ImGui::PushStyleVar(ImGuiStyleVar_FramePadding, ImVec2(0, 0));
         ImGui::PushItemWidth(ImGui::GetContentRegionAvail().x);
 
@@ -547,15 +562,16 @@ namespace hex::plugin::builtin::ui {
 
         ImGui::PopItemWidth();
         ImGui::PopStyleVar();
-        } else {
-            drawValueColumn(pattern);
-        }
     }
 
     void PatternDrawer::visit(pl::ptrn::PatternFloat& pattern) {
         createDefaultEntry(pattern);
 
-        if (this->isEditingPattern(pattern)) {
+        if (!this->isEditingPattern(pattern)) {
+            drawValueColumn(pattern);
+            return;
+        }
+
         ImGui::PushStyleVar(ImGuiStyleVar_FramePadding, ImVec2(0, 0));
         ImGui::PushItemWidth(ImGui::GetContentRegionAvail().x);
 
@@ -571,9 +587,6 @@ namespace hex::plugin::builtin::ui {
 
         ImGui::PopItemWidth();
         ImGui::PopStyleVar();
-        } else {
-            drawValueColumn(pattern);
-        }
     }
 
     void PatternDrawer::visit(pl::ptrn::PatternPadding& pattern) {
@@ -610,7 +623,11 @@ namespace hex::plugin::builtin::ui {
     void PatternDrawer::visit(pl::ptrn::PatternSigned& pattern) {
         createDefaultEntry(pattern);
 
-        if (this->isEditingPattern(pattern)) {
+        if (!this->isEditingPattern(pattern)) {
+            drawValueColumn(pattern);
+            return;
+        }
+    
         ImGui::PushStyleVar(ImGuiStyleVar_FramePadding, ImVec2(0, 0));
         ImGui::PushItemWidth(ImGui::GetContentRegionAvail().x);
 
@@ -626,16 +643,17 @@ namespace hex::plugin::builtin::ui {
 
         ImGui::PopItemWidth();
         ImGui::PopStyleVar();
-        } else {
-            drawValueColumn(pattern);
-        }
     }
 
     void PatternDrawer::visit(pl::ptrn::PatternString& pattern) {
         if (pattern.getSize() > 0) {
             createDefaultEntry(pattern);
 
-            if (this->isEditingPattern(pattern)) {
+            if (!this->isEditingPattern(pattern)) {
+                drawValueColumn(pattern);
+                return;
+            }
+            
             ImGui::PushStyleVar(ImGuiStyleVar_FramePadding, ImVec2(0, 0));
             ImGui::PushItemWidth(ImGui::GetContentRegionAvail().x);
 
@@ -647,9 +665,6 @@ namespace hex::plugin::builtin::ui {
 
             ImGui::PopItemWidth();
             ImGui::PopStyleVar();
-            } else {
-                drawValueColumn(pattern);
-            }
         }
     }
 
@@ -688,7 +703,10 @@ namespace hex::plugin::builtin::ui {
 
         }
 
-        if (open) {
+        if (!open) {
+            return;
+        }
+
         int id = 1;
         pattern.forEachEntry(0, pattern.getEntryCount(), [&](u64, auto *member){
             ImGui::PushID(id);
@@ -699,7 +717,6 @@ namespace hex::plugin::builtin::ui {
 
         closeTreeNode(pattern.isInlined());
     }
-    }
 
     void PatternDrawer::visit(pl::ptrn::PatternUnion& pattern) {
         bool open = true;
@@ -735,7 +752,10 @@ namespace hex::plugin::builtin::ui {
             }
         }
 
-        if (open) {
+        if (!open) {
+            return;
+        }
+
         int id = 1;
         pattern.forEachEntry(0, pattern.getEntryCount(), [&](u64, auto *member) {
             ImGui::PushID(id);
@@ -747,12 +767,15 @@ namespace hex::plugin::builtin::ui {
 
         closeTreeNode(pattern.isInlined());
     }
-    }
 
     void PatternDrawer::visit(pl::ptrn::PatternUnsigned& pattern) {
         createDefaultEntry(pattern);
 
-        if (this->isEditingPattern(pattern)) {
+        if (!this->isEditingPattern(pattern)) {
+            drawValueColumn(pattern);
+            return;
+        }
+
         ImGui::PushStyleVar(ImGuiStyleVar_FramePadding, ImVec2(0, 0));
         ImGui::PushItemWidth(ImGui::GetContentRegionAvail().x);
         auto value = pattern.toString();
@@ -766,9 +789,6 @@ namespace hex::plugin::builtin::ui {
         }
         ImGui::PopItemWidth();
         ImGui::PopStyleVar();
-        } else {
-            drawValueColumn(pattern);
-        }
     }
 
     void PatternDrawer::visit(pl::ptrn::PatternWideCharacter& pattern) {
@@ -828,7 +848,10 @@ namespace hex::plugin::builtin::ui {
             drawValueColumn(pattern);
         }
 
-        if (open) {
+        if (!open) {
+            return;
+        }
+
         u64 chunkCount = 0;
         for (u64 i = 0; i < iterable.getEntryCount(); i += ChunkSize) {
             chunkCount++;
@@ -843,7 +866,8 @@ namespace hex::plugin::builtin::ui {
                 if (ImGui::IsItemHovered() && ImGui::IsMouseDoubleClicked(ImGuiMouseButton_Left))
                     displayEnd += DisplayEndStep;
                 break;
-                } else {
+            }
+
             auto endIndex = std::min<u64>(iterable.getEntryCount(), i + ChunkSize);
 
             bool chunkOpen = true;
@@ -881,7 +905,10 @@ namespace hex::plugin::builtin::ui {
             }
 
 
-                    if (chunkOpen) {
+            if (!chunkOpen) {
+                continue;
+            }
+            
             int id = 1;
             iterable.forEachEntry(i, endIndex, [&](u64, auto *entry){
                 ImGui::PushID(id);
@@ -894,12 +921,9 @@ namespace hex::plugin::builtin::ui {
             if (iterable.getEntryCount() > ChunkSize)
                 ImGui::TreePop();
         }
-                }
-            }
 
         closeTreeNode(isInlined);
     }
-    }
 
     u64& PatternDrawer::getDisplayEnd(const pl::ptrn::Pattern& pattern) {
         auto it = this->m_displayEnd.find(&pattern);
@@ -953,7 +977,10 @@ namespace hex::plugin::builtin::ui {
     }
 
     bool PatternDrawer::beginPatternTable(const std::vector<std::shared_ptr<pl::ptrn::Pattern>> &patterns, std::vector<pl::ptrn::Pattern*> &sortedPatterns, float height) {
-        if (ImGui::BeginTable("##Patterntable", 8, ImGuiTableFlags_Borders | ImGuiTableFlags_Resizable | ImGuiTableFlags_Sortable | ImGuiTableFlags_Hideable | ImGuiTableFlags_Reorderable | ImGuiTableFlags_RowBg | ImGuiTableFlags_ScrollY, ImVec2(0, height))) {
+        if (!ImGui::BeginTable("##Patterntable", 8, ImGuiTableFlags_Borders | ImGuiTableFlags_Resizable | ImGuiTableFlags_Sortable | ImGuiTableFlags_Hideable | ImGuiTableFlags_Reorderable | ImGuiTableFlags_RowBg | ImGuiTableFlags_ScrollY, ImVec2(0, height))) {
+            return false;
+        }
+    
         ImGui::TableSetupScrollFreeze(0, 1);
         ImGui::TableSetupColumn("##favorite",                               ImGuiTableColumnFlags_NoSort | ImGuiTableColumnFlags_WidthFixed | ImGuiTableColumnFlags_NoResize | ImGuiTableColumnFlags_NoReorder | ImGuiTableColumnFlags_NoHide | ImGuiTableColumnFlags_IndentDisable, ImGui::GetTextLineHeight(), ImGui::GetID("favorite"));
         ImGui::TableSetupColumn("hex.builtin.pattern_drawer.var_name"_lang, ImGuiTableColumnFlags_PreferSortAscending | ImGuiTableColumnFlags_NoHide | ImGuiTableColumnFlags_IndentEnable, 0, ImGui::GetID("name"));
@@ -966,10 +993,15 @@ namespace hex::plugin::builtin::ui {
 
         auto sortSpecs = ImGui::TableGetSortSpecs();
 
-            if (patterns.empty())
+        if (patterns.empty()) {
             sortedPatterns.clear();
+            return true;
+        }
+
+        if (!sortSpecs->SpecsDirty && !sortedPatterns.empty()) {
+            return true;
+        }
         
-            if (!patterns.empty() && (sortSpecs->SpecsDirty || sortedPatterns.empty())) {
         sortedPatterns.clear();
         std::transform(patterns.begin(), patterns.end(), std::back_inserter(sortedPatterns), [](const std::shared_ptr<pl::ptrn::Pattern> &pattern) {
             return pattern.get();
@@ -985,14 +1017,10 @@ namespace hex::plugin::builtin::ui {
             });
 
         sortSpecs->SpecsDirty = false;
-            }
         
         return true;
     }
 
-        return false;
-    }
-
     void PatternDrawer::traversePatternTree(pl::ptrn::Pattern &pattern, std::vector<std::string> &patternPath, const std::function<void(pl::ptrn::Pattern&)> &callback) {
         patternPath.push_back(pattern.getVariableName());
         ON_SCOPE_EXIT { patternPath.pop_back(); };