reading screen size and handling resize signal

graph_browser.cpp

@@ -1,7 +1,8 @@
 #include <cstring>
-#include <algorithm>
 #include <cassert>
 
+#include <algorithm>
+
 #include "graph_browser.hpp"
 
 namespace {
@@ -47,6 +48,7 @@ namespace {
 
     return retval;
   }
+
 }
 
 
@@ -77,6 +79,12 @@ GraphBrowser::GraphBrowser(Graph<std::string>& g)
   , n_of_n_win_(0)
   , graph_(g)
   , history_()
+{
+  updateDimensions();
+  initLayout();
+}
+
+void GraphBrowser::initLayout()
 {
   // window of the current node
   menu_ = new_menu((ITEM **)0);
@@ -103,7 +111,7 @@ GraphBrowser::GraphBrowser(Graph<std::string>& g)
   wrefresh(n_win);
 
   // window of the neighbours'neighbours of the current vertex
-  n_of_n_win_ = newwin(window_height, TERM_MAX_X-current_window_width-n_window_width,
+  n_of_n_win_ = newwin(window_height, term_max_x_-current_window_width-n_window_width,
                     1, n_window_width+current_window_width);
   wborder(n_of_n_win_, ACS_VLINE, ACS_VLINE, ACS_HLINE, ACS_HLINE,
                     ACS_TTEE, ACS_URCORNER, ACS_BTEE, ACS_LRCORNER);
@@ -111,10 +119,11 @@ GraphBrowser::GraphBrowser(Graph<std::string>& g)
   wrefresh(n_of_n_win_);
 
   // bottom text
-  mvprintw(TERM_MAX_Y-1, 0, "ESC:exit, cursors:navigate, d/i:del/ins edge, D/I:del/ins node");
+  mvprintw(term_max_y_-1, 0, "ESC:exit, cursors:navigate, d/i:del/ins edge, D/I:del/ins node");
   refresh();
 }
 
+
 GraphBrowser::~GraphBrowser()
 {
   unpost_menu(menu_);
@@ -238,8 +247,8 @@ void GraphBrowser::updateCurrent(const std::string& s)
   addItems(n);
   updateNeighbours();
 
-  mvprintw(0, 0, "%s",std::string(TERM_MAX_X,' ').c_str());
-  mvprintw(0, 0, historyToString(history_, TERM_MAX_X).c_str());
+  mvprintw(0, 0, "%s",std::string(term_max_x_,' ').c_str());
+  mvprintw(0, 0, historyToString(history_, term_max_x_).c_str());
   refresh();
 }
 
@@ -247,7 +256,7 @@ void GraphBrowser::updateNeighbours()
 {
 
   const size_t n_width = n_window_width-1;
-  const size_t n_of_n_width = TERM_MAX_X-current_window_width-n_window_width-2;
+  const size_t n_of_n_width = term_max_x_-current_window_width-n_window_width-2;
   for (int i = 1; i < window_height-1; ++i) {
     mvwprintw(n_win, i, 1, "%s", std::string(n_width,' ').c_str());
     mvwprintw(n_of_n_win_, i, 1, "%s", std::string(n_of_n_width,' ').c_str());
@@ -304,3 +313,28 @@ void GraphBrowser::addItems(const std::vector<std::string>& stringVector)
   for (int i = 0; i < old_items_count; ++i)
     assert(free_item(old_items[i]) == E_OK);
 }
+
+void GraphBrowser::updateDimensions()
+{
+  term_max_x_ = COLS;
+  term_max_y_ = LINES;
+  window_height = term_max_y_-2;
+  current_window_width = term_max_x_/4;
+  n_window_width = term_max_x_/4;
+}
+
+void GraphBrowser::terminalResizedEvent(int)
+{
+  endwin();
+  refresh();
+  clear();
+
+  free_menu(menu_);
+  delwin(current_win_);
+  delwin(n_win);
+  delwin(n_of_n_win_);
+
+  updateDimensions();
+  initLayout();
+  updateCurrent(history_.back());
+}

graph_browser.hpp

@@ -9,10 +9,6 @@
 #include <graph/graph.hpp>
 
 class GraphBrowser {
-public:
-
-  static constexpr size_t TERM_MAX_X = 80;
-  static constexpr size_t TERM_MAX_Y = 24;
 
   static constexpr int KEY_ESC = 27;
   static constexpr int KEY_LOWER_CASE_D = 100;
@@ -20,9 +16,13 @@ public:
   static constexpr int KEY_UPPER_CASE_D = 68;
   static constexpr int KEY_UPPER_CASE_I = 73;
 
-  static constexpr size_t window_height = TERM_MAX_Y-2;
-  static constexpr size_t current_window_width = TERM_MAX_X/4;
-  static constexpr size_t n_window_width = TERM_MAX_X/4;
+  size_t term_max_x_ = 80;
+  size_t term_max_y_ = 24;
+  size_t window_height = term_max_y_-2;
+  size_t current_window_width = term_max_x_/4;
+  size_t n_window_width = term_max_x_/4;
+
+public:
 
   void static init();
   void static destroy();
@@ -32,13 +32,16 @@ public:
 
   void mainLoop();
   void setStartVertex(const std::string& s);
+  void terminalResizedEvent(int);
 
 private:
 
+  void initLayout();
   void updateCurrent(const std::string& s);
   void updateNeighbours();
   void addItems(const std::vector<std::string>& stringVector);
   void deleteElement(bool delete_node);
+  void updateDimensions();
 
   MENU *menu_;
   WINDOW *current_win_, *n_win, * n_of_n_win_;

main.cpp

@@ -1,9 +1,14 @@
 #include <graph/graph.hpp>
 
 #include <string>
+#include <signal.h>
+
+#include <functional>
 
 #include "graph_browser.hpp"
 
+using namespace std::placeholders;
+
 std::string generateRandomString(size_t length)
 {
   const char charset[] =
@@ -50,15 +55,29 @@ Graph<std::string> generateRandomGraph(size_t number_of_vertices,
   return graph;
 }
 
+std::function<void(int)> callback_function;
+
+void CallCb( int value )
+{
+  callback_function(value);
+}
+
 int main(int argc, char* argv[])
 {
   Graph<std::string> g = generateRandomGraph(10, 200, 5, 20);
 
   GraphBrowser::init();
 
-  GraphBrowser ni(g);
-  ni.setStartVertex(*g.begin());
-  ni.mainLoop();
+  GraphBrowser gb(g);
+  gb.setStartVertex(*g.begin());
+
+  callback_function = std::bind1st(std::mem_fun(&GraphBrowser::terminalResizedEvent), &gb);
+
+  struct sigaction act;
+  act.sa_handler = CallCb;
+  sigaction(SIGWINCH, &act, NULL);
+
+  gb.mainLoop();
 
   GraphBrowser::destroy();
   return EXIT_SUCCESS;