Merge 4f1a694e81 into 6440a88dc6

include/ftxui/component/screen_interactive.hpp

@@ -10,7 +10,6 @@
 #include <memory>                        // for shared_ptr
 #include <string>                        // for string
 #include <thread>                        // for thread
-#include <variant>                       // for variant
 
 #include "ftxui/component/animation.hpp"       // for TimePoint
 #include "ftxui/component/captured_mouse.hpp"  // for CapturedMouse
@@ -105,13 +104,12 @@ class ScreenInteractive : public Screen {
     Fullscreen,
     TerminalOutput,
   };
-  const Dimension dimension_ = Dimension::Fixed;
-  const bool use_alternative_screen_ = false;
-
   ScreenInteractive(Dimension dimension,
                     int dimx,
                     int dimy,
                     bool use_alternative_screen);
+  const Dimension dimension_;
+  const bool use_alternative_screen_;
 
   bool track_mouse_ = true;
 

src/ftxui/component/screen_interactive_test.cpp

@@ -10,9 +10,57 @@
 #include "ftxui/component/screen_interactive.hpp"
 #include "ftxui/dom/elements.hpp"  // for text, Element
 
+#if defined(__unix__)
+#include <fcntl.h>
+#include <unistd.h>
+#include <array>
+#include <cstdio>
+#include <ftxui/component/loop.hpp>
+#include <string>
+#endif
+
 namespace ftxui {
 
 namespace {
+#if defined(__unix__)
+
+// Capture the standard output (stdout) to a string.
+class StdCapture {
+ public:
+  explicit StdCapture(std::string* captured)
+      : captured_(captured) {
+    if (pipe(pipefd_) != 0) return;
+    old_stdout_ = dup(fileno(stdout));
+    fflush(stdout);
+    dup2(pipefd_[1], fileno(stdout));
+    close(pipefd_[1]);  // Close the write end in the parent
+  }
+
+  ~StdCapture() {
+    fflush(stdout);
+    dup2(old_stdout_, fileno(stdout));
+    close(old_stdout_);
+
+    char buffer[1024];
+    ssize_t count;
+    while ((count = read(pipefd_[0], buffer, sizeof(buffer))) > 0) {
+      captured_->append(buffer, count);
+    }
+
+    close(pipefd_[0]);
+  }
+
+  StdCapture(const StdCapture&) = delete;
+  StdCapture& operator=(const StdCapture&) = delete;
+
+ private:
+  int pipefd_[2]{-1, -1};
+  int old_stdout_{-1};
+  std::string* const captured_;
+};
+
+#endif
+
 bool TestSignal(int signal) {
   int called = 0;
   // The tree of components. This defines how to navigate using the keyboard.
@@ -131,4 +179,67 @@ TEST(ScreenInteractive, CtrlC_NotForced) {
   ASSERT_GE(ctrl_c_count, 50);
 }
 
+// Regression test for:
+// https://github.com/ArthurSonzogni/FTXUI/pull/1064/files
+TEST(ScreenInteractive, FixedSizeInitialFrame) {
+#if defined(__unix__)
+  std::string output;
+  {
+    auto capture = StdCapture(&output);
+
+    auto screen = ScreenInteractive::FixedSize(2, 2);
+    auto component = Renderer([&] {
+      return text("AB");
+    });
+
+    Loop loop(&screen, component);
+    loop.RunOnce();
+  }
+  ASSERT_EQ(
+      // Install the ScreenInteractive.
+      "\0"           // Flush stdout.
+      "\x1BP$q q"    // Set cursor shape to 1 (block).
+      "\x1B\\"       // Reset cursor position.
+      "\x1B[?7l"     // Disable line wrapping.
+      "\x1B[?1000h"  // Enable mouse tracking.
+      "\x1B[?1003h"  // Enable mouse motion tracking.
+      "\x1B[?1015h"  // Enable mouse wheel tracking.
+      "\x1B[?1006h"  // Enable SGR mouse tracking.
+      "\0"           // Flush stdout.
+
+      // Reset the screen.
+      "\r"       // Reset cursor position.
+      "\x1B[2K"  // Clear the line.
+      "\x1B[1A"  // Move cursor up one line.
+      "\x1B[2K"  // Clear the line.
+
+      // Print the document.
+      "AB\r\n"  // Print "AB" and move to the next line.
+      "  "      // Print two spaces to fill the line.
+
+      // Set cursor position.
+      "\x1B[1D"    // Move cursor left one character.
+      "\x1B[?25l"  // Hide cursor.
+
+      // Flush
+      "\0"  // Flush stdout.
+
+      // Uninstall the ScreenInteractive.
+      "\x1B[1C"      // Move cursor right one character.
+      "\x1B[?1006l"  // Disable SGR mouse tracking.
+      "\x1B[?1015l"  // Disable mouse wheel tracking.
+      "\x1B[?1003l"  // Disable mouse motion tracking.
+      "\x1B[?1000l"  // Disable mouse tracking.
+      "\x1B[?7h"     // Enable line wrapping.
+      "\x1B[?25h"    // Show cursor.
+      "\x1B[1 q"     // Set cursor shape to 1 (block).
+      "\0"           // Flush stdout.
+
+      // Skip one line to avoid the prompt to be printed over the last drawing.
+      "\r\n",
+      output);
+#endif
+
+}
+
 }  // namespace ftxui