From c39fb0e6da7a8b76c754399ae32d36936a94cd3e Mon Sep 17 00:00:00 2001
From: chatlanin <zimin@chatlanin.com.ru>
Date: Mon, 27 Mar 2023 10:48:39 +0300
Subject: [PATCH] add navigation up down

---
 src/rrr/content/content.cpp                   |  2 -
 .../gui/browser/navigation/navigation.cpp     | 59 ++++++++++++++++++-
 .../gui/browser/navigation/navigation.hpp     |  5 ++
 src/rrr/rrr.hpp                               |  8 +--
 4 files changed, 67 insertions(+), 7 deletions(-)

diff --git a/src/rrr/content/content.cpp b/src/rrr/content/content.cpp
index 9e0c5cc..c212214 100644
--- a/src/rrr/content/content.cpp
+++ b/src/rrr/content/content.cpp
@@ -18,8 +18,6 @@ namespace rrr
     nav.fill(PWD);
     his.fill(PWD);
     prev.fill(nav.data.at(navigation_cursor_position).path);
-
-    hack::log()(prev.data.size());
   }
 
   files* content::get(TYPE_WIN type)
diff --git a/src/rrr/layers/gui/browser/navigation/navigation.cpp b/src/rrr/layers/gui/browser/navigation/navigation.cpp
index 4d9bd15..5c0c57d 100644
--- a/src/rrr/layers/gui/browser/navigation/navigation.cpp
+++ b/src/rrr/layers/gui/browser/navigation/navigation.cpp
@@ -37,8 +37,12 @@ namespace rrr::layers::gui
     pos.y += 9.f; // небольшой отступ сверху
     ImGui::SetCursorPosY(pos.y);
 
-    for (auto& item : *data)
+    auto begin = data->begin() + delta;
+    auto end = data->end();
+
+    for (files::iterator it = begin; it != end; ++it)
     {
+      auto item = *it;
       ImGui::PushID(item.id);
 
       push_style(item);
@@ -52,6 +56,7 @@ namespace rrr::layers::gui
 
         ImGui::TextUnformatted(">");
         ImGui::SameLine(22.f);
+        current_position = it - data->begin();
       }
       else
       {
@@ -175,12 +180,14 @@ namespace rrr::layers::gui
     {
       cnt->increment_position(STEP_DOWN);
       em->execute(types::event_type::NAVIGATION_DOWN, nullptr);
+      set_delta(MOVE_DIRECTION::DOWN);
     }
 
     if (key.get_keycode() == try_engine::key::K)
     {
       cnt->increment_position(STEP_UP);
       em->execute(types::event_type::NAVIGATION_UP, nullptr);
+      set_delta(MOVE_DIRECTION::UP);
     }
 
     if (key.get_keycode() == try_engine::key::H)
@@ -221,4 +228,54 @@ namespace rrr::layers::gui
     if (key.get_keycode() == try_engine::key::LEFTSHIFT || key.get_keycode() == try_engine::key::RIGHTSHIFT)
       shift = false;
   }
+
+  void navigation::set_delta(MOVE_DIRECTION mvd)
+  {
+    auto row_size = 26.3f; // высота вы пикселях одной строки списка
+    int h = height / row_size;  // высота в строках списка всего столбца экрана
+    auto big_content = height < data->size() * row_size;
+
+    static auto cursor_position = 0; // позиция курсора относительно высоты экрана
+    int size = data->size();
+
+    if (big_content)
+    {
+      if (mvd == MOVE_DIRECTION::DOWN)
+      {
+        ++cursor_position;
+
+        // на самом деле получаем его выше, но делаем такой трюк 
+        // т.к. происходит задержка на один ход нажатия клавиши
+        ++current_position; 
+        if (current_position >= size) current_position = size - 1;
+
+        bool is_end = size - current_position <= 10;
+        if (cursor_position >= h - 10 &&  !is_end)
+        {
+          ++delta;
+          cursor_position = h - 10;
+        }
+
+        if (cursor_position >= h) cursor_position = h;
+      }
+
+      if (mvd == MOVE_DIRECTION::UP)
+      {
+        --cursor_position;
+        --current_position;
+
+        if (cursor_position <= 10) 
+          --delta;
+
+        if (cursor_position < 10 && current_position > 12)
+          cursor_position = 10;
+        
+        if (delta < 0) 
+        {
+          delta = 0;
+          cursor_position = 0;
+        }
+      }
+    }
+  }
 }
diff --git a/src/rrr/layers/gui/browser/navigation/navigation.hpp b/src/rrr/layers/gui/browser/navigation/navigation.hpp
index e12234f..e669861 100644
--- a/src/rrr/layers/gui/browser/navigation/navigation.hpp
+++ b/src/rrr/layers/gui/browser/navigation/navigation.hpp
@@ -43,12 +43,16 @@ namespace rrr::layers::gui
       const int STEP_DOWN = 1;
       file selected_file;
       bool shift = false;
+      int current_position = 0;
+      int delta = 0;
 
     private:
       const ImVec4 dir_color = func::get_IMGUI_color<ImVec4>(91.f, 128.f, 191.f);
       const ImVec4 file_color = func::get_IMGUI_color<ImVec4>(186.f, 186.f, 186.f);
       const ImVec4 link_color = func::get_IMGUI_color<ImVec4>(51.f, 95.f, 165.f);
 
+      enum class MOVE_DIRECTION { UP, DOWN };
+
     private:
       void resize();
       void pressed(system_event& e);
@@ -57,6 +61,7 @@ namespace rrr::layers::gui
       void push_style(file&);
       void pop_style(file&);
       std::string get_file_content(file&);
+      void set_delta(MOVE_DIRECTION);
   };
 }
 
diff --git a/src/rrr/rrr.hpp b/src/rrr/rrr.hpp
index d5766b3..b8120be 100644
--- a/src/rrr/rrr.hpp
+++ b/src/rrr/rrr.hpp
@@ -11,17 +11,17 @@ namespace rrr
 {
   using event_manager = try_engine::app_event::event;
 
-  class engine : public try_engine::application
+  class rrr_impl : public try_engine::application
   {
     public:
-      engine(std::string app_name) : try_engine::application{ app_name }
+      rrr_impl(std::string app_name) : try_engine::application{ app_name }
       { 
         // HERE
         // убрать это в релизе
         cnt.set_pwd("/mnt/develop/projects/cpp/rrr/dir_for_tests");
         cnt.fill(); 
       };
-      ~engine() = default;
+      ~rrr_impl() = default;
 
     public:
       template<typename... Args>
@@ -42,7 +42,7 @@ namespace try_engine
 {
   inline application& create()
   {
-    static  rrr::engine e { "rrr.v2" };
+    static  rrr::rrr_impl e { "rrr.v2" };
 
     e.push_layer(
       new rrr::layers::gui::history{},