From b50f1fffc8f63d25d0dc25b533ebb62089a69542 Mon Sep 17 00:00:00 2001
From: Igor Bogoslavskyi <niosus@users.noreply.github.com>
Date: Wed, 26 Jul 2023 00:41:16 +0200
Subject: [PATCH] Improve const correctness in the Screen class (#701)
- Add a const variant to the accessor functions
- Make Print and ToString functions const
This fixes: https://github.com/ArthurSonzogni/FTXUI/issues/700
---
include/ftxui/screen/screen.hpp | 15 ++++++++-----
src/ftxui/screen/screen.cpp | 37 ++++++++++++++++++++++++---------
2 files changed, 37 insertions(+), 15 deletions(-)
diff --git a/include/ftxui/screen/screen.hpp b/include/ftxui/screen/screen.hpp
index 68cb331c..b4442407 100644
--- a/include/ftxui/screen/screen.hpp
+++ b/include/ftxui/screen/screen.hpp
@@ -66,13 +66,18 @@ class Screen {
static Screen Create(Dimensions dimension);
static Screen Create(Dimensions width, Dimensions height);
- // Node write into the screen using Screen::at.
+ // Access a character in the grid at a given position.
std::string& at(int x, int y);
+ const std::string& at(int x, int y) const;
+
+ // Access a cell (Pixel) in the grid at a given position.
Pixel& PixelAt(int x, int y);
+ const Pixel& PixelAt(int x, int y) const;
+
+ std::string ToString() const;
- // Convert the screen into a printable string in the terminal.
- std::string ToString();
- void Print();
+ // Print the Screen on to the terminal.
+ void Print() const;
// Get screen dimensions.
int dimx() const { return dimx_; }
@@ -81,7 +86,7 @@ class Screen {
// Move the terminal cursor n-lines up with n = dimy().
std::string ResetPosition(bool clear = false) const;
- // Fill with space.
+ // Fill the screen with space.
void Clear();
void ApplyShader();
diff --git a/src/ftxui/screen/screen.cpp b/src/ftxui/screen/screen.cpp
index dd0570f4..3eb5492d 100644
--- a/src/ftxui/screen/screen.cpp
+++ b/src/ftxui/screen/screen.cpp
@@ -428,9 +428,11 @@ Screen::Screen(int dimx, int dimy)
#endif
}
-/// Produce a std::string that can be used to print the Screen on the terminal.
-/// Don't forget to flush stdout. Alternatively, you can use Screen::Print();
-std::string Screen::ToString() {
+/// Produce a std::string that can be used to print the Screen on the
+/// terminal.
+/// @note Don't forget to flush stdout. Alternatively, you can use
+/// Screen::Print();
+std::string Screen::ToString() const {
std::stringstream ss;
Pixel previous_pixel;
@@ -456,24 +458,39 @@ std::string Screen::ToString() {
return ss.str();
}
-void Screen::Print() {
+// Print the Screen to the terminal.
+void Screen::Print() const {
std::cout << ToString() << '\0' << std::flush;
}
-/// @brief Access a character a given position.
-/// @param x The character position along the x-axis.
-/// @param y The character position along the y-axis.
+/// @brief Access a character in a cell at a given position.
+/// @param x The cell position along the x-axis.
+/// @param y The cell position along the y-axis.
std::string& Screen::at(int x, int y) {
return PixelAt(x, y).character;
}
-/// @brief Access a Pixel at a given position.
-/// @param x The pixel position along the x-axis.
-/// @param y The pixel position along the y-axis.
+/// @brief Access a character in a cell at a given position.
+/// @param x The cell position along the x-axis.
+/// @param y The cell position along the y-axis.
+const std::string& Screen::at(int x, int y) const {
+ return PixelAt(x, y).character;
+}
+
+/// @brief Access a cell (Pixel) at a given position.
+/// @param x The cell position along the x-axis.
+/// @param y The cell position along the y-axis.
Pixel& Screen::PixelAt(int x, int y) {
return stencil.Contain(x, y) ? pixels_[y][x] : dev_null_pixel();
}
+/// @brief Access a cell (Pixel) at a given position.
+/// @param x The cell position along the x-axis.
+/// @param y The cell position along the y-axis.
+const Pixel& Screen::PixelAt(int x, int y) const {
+ return stencil.Contain(x, y) ? pixels_[y][x] : dev_null_pixel();
+}
+
/// @brief Return a string to be printed in order to reset the cursor position
/// to the beginning of the screen.
///
--
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