From 2370e70cfcb3de4c23cc0c306e2ddd082c74d3e7 Mon Sep 17 00:00:00 2001
From: Your Name <you@example.com>
Date: Thu, 27 Jan 2022 22:26:44 +0100
Subject: [PATCH] Fixed parent management for folder navigation.

---
 include/EventManager.hpp      | 11 +++---
 include/TreeNodeDiskUsage.hpp |  4 ---
 src/EventManager.cpp          | 63 +++++++++++++++++------------------
 src/TreeNodeDiskUsage.cpp     | 13 --------
 src/main.cpp                  |  1 -
 src/test.cpp                  |  1 -
 6 files changed, 37 insertions(+), 56 deletions(-)

diff --git a/include/EventManager.hpp b/include/EventManager.hpp
index d68fdf6..c0d7de6 100644
--- a/include/EventManager.hpp
+++ b/include/EventManager.hpp
@@ -8,6 +8,7 @@
 #include <unistd.h>
 #include <fcntl.h>
 #include <termios.h>
+#include <list>
 
 #include <Display.hpp>
 #include <TreeNodeDiskUsage.hpp>
@@ -49,11 +50,11 @@ class EventManager
         Display & display;
         TreeNodeDiskUsage & rootNode;
 
-        int topLine;                    //<! Index of top displayed line (for scrolling)
-        int currentLine;                //<! Currently selected line
-        TreeNodeDiskUsage *currentNode; //<! Pointer to the currently displayed node.
-        int sortType;                   //<! Entry sort type : 0 -> size descending, 1 -> name ascending
-        bool SI_units;                  //<! Indicates whether SI units should be used.
+        int topLine;                                    //<! Index of top displayed line (for scrolling)
+        int currentLine;                                //<! Currently selected line
+        std::list<TreeNodeDiskUsage*> displayedNodes;   //<! List of pointers to the successively displayed nodes.
+        int sortType;                                   //<! Entry sort type : 0 -> size descending, 1 -> name ascending
+        bool SI_units;                                  //<! Indicates whether SI units should be used.
 };
 
 #endif
diff --git a/include/TreeNodeDiskUsage.hpp b/include/TreeNodeDiskUsage.hpp
index ccc86f5..942e7e9 100644
--- a/include/TreeNodeDiskUsage.hpp
+++ b/include/TreeNodeDiskUsage.hpp
@@ -68,9 +68,6 @@ class TreeNodeDiskUsage
 		/// Returns a reference to the the child i.
 		TreeNodeDiskUsage & GetChild(unsigned int i);
 
-		/// Builds the parent links. Must be called after the tree has been built.
-		void BuildParentLinks();
-
 		/// Sorts the children of the node by size in descending order.
 		void SortBySizeDesc(bool recursive = false);
 
@@ -103,7 +100,6 @@ class TreeNodeDiskUsage
 		
 		std::string path;								//<! Path of the node
 		std::vector<TreeNodeDiskUsage> children;		//<! Stores all the children contained within the folder.
-		TreeNodeDiskUsage * parentNode;					//<! Pointer to the parent of the node.
 		bool isFolder;									//<! Indicates whether the node is a folder or a file.
 		size_t totalSize;								//<! Total size of the node, taking all children into account.
 		size_t totalSizeOnDisk;							//<! Total size of the node on the disk, taking all children into account.
diff --git a/src/EventManager.cpp b/src/EventManager.cpp
index c1d6e5c..b419d09 100644
--- a/src/EventManager.cpp
+++ b/src/EventManager.cpp
@@ -14,10 +14,10 @@ EventManager::EventManager(Display & display_, TreeNodeDiskUsage & rootNode_)
    rootNode(rootNode_),
    topLine(0),
    currentLine(0),
-   currentNode(&rootNode),
    sortType(0),
    SI_units(true)
 {
+    displayedNodes.push_back(&rootNode);
     SortNodeElements();
     UpdateScreen();
 }
@@ -109,41 +109,41 @@ void EventManager::MainEventLoop()
 
 void EventManager::CallbackArrowUp()
 {
-    if(currentNode == NULL) return;
-    if(currentNode->GetChildrenCount())
-        currentLine = ((currentLine - 1) < 0) ? (currentNode->GetChildrenCount() - 1) : ((currentLine - 1) % currentNode->GetChildrenCount());
+    if(displayedNodes.back() == NULL) return;
+    if(displayedNodes.back()->GetChildrenCount())
+        currentLine = ((currentLine - 1) < 0) ? (displayedNodes.back()->GetChildrenCount() - 1) : ((currentLine - 1) % displayedNodes.back()->GetChildrenCount());
     ScrollList();
     UpdateScreen();
 }
 
 void EventManager::CallbackArrowDown()
 {
-    if(currentNode == NULL) return;
-    if(currentNode->GetChildrenCount())
-        currentLine = (currentLine + 1) % currentNode->GetChildrenCount();
+    if(displayedNodes.back() == NULL) return;
+    if(displayedNodes.back()->GetChildrenCount())
+        currentLine = (currentLine + 1) % displayedNodes.back()->GetChildrenCount();
     ScrollList();
     UpdateScreen();
 }
 
 void EventManager::CallbackArrowLeft()
 {
-    if(currentNode == NULL) return;
+    if(displayedNodes.back() == NULL) return;
     CallbackBackspace();
 }
 
 void EventManager::CallbackArrowRight()
 {
-    if(currentNode == NULL) return;
+    if(displayedNodes.back() == NULL) return;
     CallbackEnter();
 }
 
 void EventManager::CallbackEnter()
 {
-    if(currentNode == NULL) return;
-    if((size_t)currentLine < currentNode->GetChildrenCount())
-        if(currentNode->GetChild(currentLine).IsFolder())
+    if(displayedNodes.back() == NULL) return;
+    if((size_t)currentLine < displayedNodes.back()->GetChildrenCount())
+        if(displayedNodes.back()->GetChild(currentLine).IsFolder())
         {
-            currentNode = &currentNode->GetChild(currentLine);
+            displayedNodes.push_back(&displayedNodes.back()->GetChild(currentLine));
             SortNodeElements();
             topLine = 0;
             currentLine = 0;
@@ -153,11 +153,11 @@ void EventManager::CallbackEnter()
 
 void EventManager::CallbackBackspace()
 {
-    if(currentNode == NULL) return;
+    if(displayedNodes.back() == NULL) return;
     // Go up one level
-    if(currentNode->GetParent() != NULL)
+    if(displayedNodes.size() > 1)
     {
-        currentNode = currentNode->GetParent();
+        displayedNodes.pop_back();
         topLine = 0;
         currentLine = 0;
     }
@@ -166,9 +166,9 @@ void EventManager::CallbackBackspace()
 
 void EventManager::CallbackHome()
 {
-    if(currentNode == NULL) return;
     // Set the current node to be the root node (go back "home").
-    currentNode = &rootNode;
+    displayedNodes.clear();
+    displayedNodes.push_back(&rootNode);
     topLine = 0;
     currentLine = 0;
     UpdateScreen();
@@ -176,14 +176,14 @@ void EventManager::CallbackHome()
 
 void EventManager::CallbackHelp()
 {
-    if(currentNode == NULL) return;
+    if(displayedNodes.back() == NULL) return;
     
     UpdateScreen();
 }
 
 void EventManager::CallbackSort()
 {
-    if(currentNode == NULL) return;
+    if(displayedNodes.back() == NULL) return;
     sortType = (sortType + 1) % 2;// Cycle through all the sort types.
     SortNodeElements();
     UpdateScreen();
@@ -191,15 +191,15 @@ void EventManager::CallbackSort()
 
 void EventManager::CallbackUnits()
 {
-    if(currentNode == NULL) return;
+    if(displayedNodes.back() == NULL) return;
     SI_units ^= true;// Invert the SI_units flag.
     UpdateScreen();
 }
 
 void EventManager::ScrollList()
 {
-    /*if(currentNode == NULL) return;
-    if(currentNode->GetChildrenCount())
+    /*if(displayedNodes.back() == NULL) return;
+    if(displayedNodes.back()->GetChildrenCount())
     {
         // compute visibility of selected line and scroll if needed
         PRINT_VAR(2 + currentLine - topLine);
@@ -211,18 +211,18 @@ void EventManager::ScrollList()
 
 void EventManager::SortNodeElements()
 {
-    if(currentNode == NULL) return;
+    if(displayedNodes.back() == NULL) return;
     if(sortType == 0)
-        currentNode->SortBySizeDesc();
+        displayedNodes.back()->SortBySizeDesc();
     else if(sortType == 1)
-        currentNode->SortByNameAsc();
+        displayedNodes.back()->SortByNameAsc();
 }
 
 void EventManager::UpdateScreen()
 {
     //DebugPrintState(); return;// DEBUG
     Display::ClearScreen();
-    display.DisplayTreeNode(*currentNode, topLine, SI_units);
+    display.DisplayTreeNode(*displayedNodes.back(), topLine, SI_units);
     display.HighlightLine(2 + topLine + currentLine, true);
     display.DrawScreenLines();
 }
@@ -232,14 +232,13 @@ void EventManager::DebugPrintState()
     PRINT_VAR(&rootNode);
     PRINT_VAR(topLine);
     PRINT_VAR(currentLine);
-    PRINT_VAR(currentNode);
-    PRINT_VAR(currentNode->GetParent());
+    PRINT_VAR(displayedNodes.back());
     PRINT_VAR(sortType);
 
-    if((size_t)currentLine < currentNode->GetChildrenCount())
+    if((size_t)currentLine < displayedNodes.back()->GetChildrenCount())
     {
-        PRINT_VAR(currentNode->GetChild(currentLine).IsFolder());
-        PRINT_VAR(currentNode->GetChild(currentLine).GetNodePath());
+        PRINT_VAR(displayedNodes.back()->GetChild(currentLine).IsFolder());
+        PRINT_VAR(displayedNodes.back()->GetChild(currentLine).GetNodePath());
     }
     std::cout << "-----------------------------------------------\n";
 }
diff --git a/src/TreeNodeDiskUsage.cpp b/src/TreeNodeDiskUsage.cpp
index 8e65743..b7ad6e8 100644
--- a/src/TreeNodeDiskUsage.cpp
+++ b/src/TreeNodeDiskUsage.cpp
@@ -3,7 +3,6 @@
 TreeNodeDiskUsage::TreeNodeDiskUsage(std::string const& path_, PathFilters const* pathFilters_)
 : pathFilters(pathFilters_),
   path(path_),
-  parentNode(NULL),
   isFolder(false),
   totalSize(0),
   totalSizeOnDisk(0),
@@ -167,8 +166,6 @@ std::string TreeNodeDiskUsage::GetNodeName() const
 	return path.substr(lastSepPos+1, path.size()-lastSepPos-1);
 }
 
-TreeNodeDiskUsage * TreeNodeDiskUsage::GetParent() const { return parentNode; }
-
 bool TreeNodeDiskUsage::IsFolder() const { return isFolder; }
 
 std::vector<TreeNodeDiskUsage> const& TreeNodeDiskUsage::GetChildren() const { return children; }
@@ -187,16 +184,6 @@ void TreeNodeDiskUsage::SortBySizeDesc(bool recursive)
 			children[i].SortBySizeDesc(recursive);
 }
 
-void TreeNodeDiskUsage::BuildParentLinks()
-{
-	for(unsigned int i = 0 ; i < children.size() ; i++)
-	{
-		children[i].parentNode = this;
-		if(children[i].isFolder)
-			children[i].BuildParentLinks();
-	}
-}
-
 void TreeNodeDiskUsage::SortByNameAsc(bool recursive)
 {
 	std::sort(children.begin(), children.end(), TreeNodeDiskUsage::SortOperatorNameAsc);
diff --git a/src/main.cpp b/src/main.cpp
index 019911d..bd6db65 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -84,7 +84,6 @@ int main(int argc, char *argv[])
 	// Interactive mode : the user can navigate through the tree structure.
 	else
 	{
-		tree.BuildParentLinks();
 		EventManager eventManager(display, tree);
 		eventManager.MainEventLoop();
 	}
diff --git a/src/test.cpp b/src/test.cpp
index fc99363..e22b49e 100644
--- a/src/test.cpp
+++ b/src/test.cpp
@@ -194,7 +194,6 @@ void runTests(int argc, char *argv[])
 		Display display;
 		TreeNodeDiskUsage tree(rootpath);
 		tree.BuildTree(false);
-		tree.BuildParentLinks();
 		EventManager eventManager(display, tree);
 		eventManager.MainEventLoop();
 	}