alternative_buffer scope object

Author: ianthomas23

CMakeLists.txt

@@ -64,6 +64,7 @@ set(GIT2CPP_SRC
     ${GIT2CPP_SOURCE_DIR}/utils/common.hpp
     ${GIT2CPP_SOURCE_DIR}/utils/git_exception.cpp
     ${GIT2CPP_SOURCE_DIR}/utils/git_exception.hpp
+    ${GIT2CPP_SOURCE_DIR}/utils/output.cpp
     ${GIT2CPP_SOURCE_DIR}/utils/output.hpp
     ${GIT2CPP_SOURCE_DIR}/utils/terminal_pager.cpp
     ${GIT2CPP_SOURCE_DIR}/utils/terminal_pager.hpp

src/utils/output.cpp

@@ -0,0 +1,23 @@
+#include "output.hpp"
+
+// OS-specific libraries.
+#include <sys/ioctl.h>
+
+alternative_buffer::alternative_buffer()
+{
+    tcgetattr(fileno(stdin), &m_previous_termios);
+    auto new_termios = m_previous_termios;
+    // Disable canonical mode (buffered I/O) and echo from stdin to stdout.
+    new_termios.c_lflag &= (~ICANON & ~ECHO);
+    tcsetattr(fileno(stdin), TCSANOW, &new_termios);
+
+    std::cout << ansi_code::enable_alternative_buffer;
+}
+
+alternative_buffer::~alternative_buffer()
+{
+    std::cout << ansi_code::disable_alternative_buffer;
+
+    // Restore previous termios settings.
+    tcsetattr(fileno(stdin), TCSANOW, &m_previous_termios);
+}

src/utils/output.hpp

@@ -4,6 +4,9 @@
 #include "ansi_code.hpp"
 #include "common.hpp"
 
+// OS-specific libraries.
+#include <termios.h>
+
 // Scope object to hide the cursor. This avoids
 // cursor twinkling when rewritting the same line
 // too frequently.
@@ -19,3 +22,16 @@ struct cursor_hider : noncopyable_nonmovable
         std::cout << ansi_code::show_cursor;
     }
 };
+
+// Scope object to use alternative output buffer for
+// fullscreen interactive terminal input/output.
+class alternative_buffer : noncopyable_nonmovable
+{
+public:
+    alternative_buffer();
+
+    ~alternative_buffer();
+
+private:
+    struct termios m_previous_termios;
+};

src/utils/terminal_pager.cpp

@@ -6,11 +6,11 @@
 
 // OS-specific libraries.
 #include <sys/ioctl.h>
-#include <termios.h>
 
 #include <termcolor/termcolor.hpp>
 
 #include "ansi_code.hpp"
+#include "output.hpp"
 #include "terminal_pager.hpp"
 
 terminal_pager::terminal_pager()
@@ -181,14 +181,7 @@ void terminal_pager::show()
         return;
     }
 
-    struct termios old_termios;
-    tcgetattr(fileno(stdin), &old_termios);
-    auto new_termios = old_termios;
-    // Disable canonical mode (buffered I/O) and echo from stdin to stdout.
-    new_termios.c_lflag &= (~ICANON & ~ECHO);
-    tcsetattr(fileno(stdin), TCSANOW, &new_termios);
-
-    std::cout << ansi_code::enable_alternative_buffer;
+    alternative_buffer alt_buffer;
 
     m_start_row_index = 0;
     render_terminal();
@@ -199,11 +192,6 @@ void terminal_pager::show()
         stop = process_input(get_input());
     } while (!stop);
 
-    std::cout << ansi_code::disable_alternative_buffer;
-
-    // Restore original termios settings.
-    tcsetattr(fileno(stdin), TCSANOW, &old_termios);
-
     m_lines.clear();
     m_start_row_index = 0;
 }