Feature: Canvas (#287)

Draw using braille and block characters on a grid.

examples/CMakeLists.txt

@@ -1,7 +1,7 @@
 set(EXAMPLES_DIR ${CMAKE_CURRENT_SOURCE_DIR})
 function(example name)
-  add_executable(${name} ${name}.cpp)
-  target_link_libraries(${name} PUBLIC ${DIRECTORY_LIB})
+  add_executable(ftxui_example_${name} ${name}.cpp)
+  target_link_libraries(ftxui_example_${name} PUBLIC ${DIRECTORY_LIB})
   file(RELATIVE_PATH dir ${EXAMPLES_DIR} ${CMAKE_CURRENT_SOURCE_DIR})
   set_property(GLOBAL APPEND PROPERTY FTXUI::EXAMPLES ${dir}/${name})
 endfunction(example)

examples/component/CMakeLists.txt

@@ -1,16 +1,17 @@
 set(DIRECTORY_LIB component)
 
 example(button)
+example(canvas_animated)
 example(checkbox)
 example(checkbox_in_frame)
 example(composition)
 example(dropdown)
-example(flexbox)
+example(flexbox_gallery)
+example(focus)
 example(gallery)
 example(homescreen)
 example(input)
 example(maybe)
-example(focus)
 example(menu)
 example(menu2)
 example(menu_entries)

examples/component/canvas_animated.cpp

@@ -0,0 +1,257 @@
+#include <stddef.h>                // for size_t
+#include <stdio.h>                 // for getchar
+#include <ftxui/dom/elements.hpp>  // for operator|, size, Element, text, hcenter, Decorator, Fit, WIDTH, hflow, window, EQUAL, GREATER_THAN, HEIGHT, bold, border, dim, LESS_THAN
+#include <ftxui/screen/screen.hpp>  // for Full, Screen
+#include <memory>                   // for allocator, shared_ptr
+#include <string>  // for operator+, to_string, char_traits, string
+
+#include "ftxui/component/component.hpp"
+#include "ftxui/component/screen_interactive.hpp"
+
+#include <cmath>
+int main(int argc, const char* argv[]) {
+  using namespace ftxui;
+
+  int mouse_x = 0;
+  int mouse_y = 0;
+
+  // A triangle following the mouse, using braille characters.
+  auto renderer_line_braille = Renderer([&] {
+    auto c = Canvas(100, 100);
+    c.DrawText(0,0, "Several lines (braille)");
+    c.DrawPointLine(mouse_x, mouse_y, 80, 10, Color::Red);
+    c.DrawPointLine(80, 10, 80, 40, Color::Blue);
+    c.DrawPointLine(80, 40, mouse_x, mouse_y, Color::Green);
+    return ElementFrom(std::move(c));
+  });
+
+  // A triangle following the mouse, using block characters.
+  auto renderer_line_block = Renderer([&] {
+    auto c = Canvas(100, 100);
+    c.DrawText(0,0, "Several lines (block)");
+    c.DrawBlockLine(mouse_x, mouse_y, 80, 10, Color::Red);
+    c.DrawBlockLine(80, 10, 80, 40, Color::Blue);
+    c.DrawBlockLine(80, 40, mouse_x, mouse_y, Color::Green);
+    return ElementFrom(std::move(c));
+  });
+
+  // A circle following the mouse, using braille characters.
+  auto renderer_circle_braille = Renderer([&] {
+    auto c = Canvas(100, 100);
+    c.DrawText(0,0, "A circle (braille)");
+    c.DrawPointCircle(mouse_x, mouse_y, 30);
+    return ElementFrom(std::move(c));
+  });
+
+  // A circle following the mouse, using block characters.
+  auto renderer_circle_block = Renderer([&] {
+    auto c = Canvas(100, 100);
+    c.DrawText(0,0, "A circle (block)");
+    c.DrawBlockCircle(mouse_x, mouse_y, 30);
+    return ElementFrom(std::move(c));
+  });
+
+  // A filled circle following the mouse, using braille characters.
+  auto renderer_circle_filled_braille = Renderer([&] {
+    auto c = Canvas(100, 100);
+    c.DrawText(0,0, "A circle filled (braille)");
+    c.DrawPointCircleFilled(mouse_x, mouse_y, 30);
+    return ElementFrom(std::move(c));
+  });
+
+  // A filled circle following the mouse, using block characters.
+  auto renderer_circle_filled_block = Renderer([&] {
+    auto c = Canvas(100, 100);
+    c.DrawText(0,0, "A circle filled (block)");
+    c.DrawBlockCircleFilled(mouse_x, mouse_y, 30);
+    return ElementFrom(std::move(c));
+  });
+
+  // An ellipse following the mouse, using braille characters.
+  auto renderer_ellipse_braille = Renderer([&] {
+    auto c = Canvas(100, 100);
+    c.DrawText(0,0, "An ellipse (braille)");
+    c.DrawPointEllipse(mouse_x / 2, mouse_y / 2, mouse_x / 2, mouse_y / 2);
+    return ElementFrom(std::move(c));
+  });
+
+  // An ellipse following the mouse, using block characters.
+  auto renderer_ellipse_block = Renderer([&] {
+    auto c = Canvas(100, 100);
+    c.DrawText(0,0, "An ellipse (block)");
+    c.DrawBlockEllipse(mouse_x / 2, mouse_y / 2, mouse_x / 2, mouse_y / 2);
+    return ElementFrom(std::move(c));
+  });
+
+  // An ellipse following the mouse filled, using braille characters.
+  auto renderer_ellipse_filled_braille = Renderer([&] {
+    auto c = Canvas(100, 100);
+    c.DrawText(0,0, "A filled ellipse (braille)");
+    c.DrawPointEllipseFilled(mouse_x / 2, mouse_y / 2, mouse_x / 2,
+                              mouse_y / 2);
+    return ElementFrom(std::move(c));
+  });
+
+  // An ellipse following the mouse filled, using block characters.
+  auto renderer_ellipse_filled_block = Renderer([&] {
+    auto c = Canvas(100, 100);
+    c.DrawText(0,0, "A filled ellipse (block)");
+    c.DrawBlockEllipseFilled(mouse_x / 2, mouse_y / 2, mouse_x / 2,
+                              mouse_y / 2);
+    c.DrawBlockEllipse(mouse_x / 2, mouse_y / 2, mouse_x / 2, mouse_y / 2);
+    return ElementFrom(std::move(c));
+  });
+
+  // A text following the mouse
+  auto renderer_text = Renderer([&] {
+    auto c = Canvas(100, 100);
+    c.DrawText(0, 0, "A piece of text");
+    c.DrawText(mouse_x, mouse_y, "This is a piece of text with effects",
+               [](Pixel& p) {
+                 p.foreground_color = Color::Red;
+                 p.underlined = true;
+                 p.bold = true;
+               });
+    return ElementFrom(std::move(c));
+  });
+
+  auto renderer_plot_1 = Renderer([&] {
+    auto c = Canvas(100, 100);
+    c.DrawText(0, 0, "A graph");
+
+    std::vector<int> ys(100);
+    for (int x = 0; x < 100; x++) {
+      float dx = x - mouse_x;
+      float dy = 50;
+      ys[x] = dy + 20 * cos(dx * 0.14) + 10 * sin(dx * 0.42);
+    }
+    for (int x = 1; x < 99; x++)
+      c.DrawPointLine(x, ys[x], x + 1, ys[x + 1]);
+
+    return ElementFrom(std::move(c));
+  });
+
+  auto renderer_plot_2 = Renderer([&] {
+    auto c = Canvas(100, 100);
+    c.DrawText(0, 0, "A symmetrical graph filled");
+    std::vector<int> ys(100);
+    for (int x = 0; x < 100; x++) {
+      ys[x] = 30 +  //
+              10 * cos(x * 0.2 - mouse_x * 0.05) + //
+              5 * sin(x * 0.4) + //
+              5 * sin(x * 0.3 - mouse_y * 0.05); //
+    }
+    for (int x = 0; x < 100; x++) {
+      c.DrawPointLine(x, 50+ys[x], x, 50-ys[x], Color::Red);
+    }
+
+    return ElementFrom(std::move(c));
+  });
+
+  auto renderer_plot_3 = Renderer([&] {
+    auto c = Canvas(100, 100);
+    c.DrawText(0, 0, "A 2D gaussian plot");
+    int size = 15;
+
+    // mouse_x = 5mx + 3*my 
+    // mouse_y = 0mx + -5my + 90
+    float my = (mouse_y - 90) / -5.f;
+    float mx = (mouse_x - 3 * my) / 5.f;
+    std::vector<std::vector<float>> ys(size, std::vector<float>(size));
+    for (int y = 0; y < size; y++) {
+      for (int x = 0; x < size; x++) {
+        float dx = x-mx;
+        float dy = y-my;
+        ys[y][x] = -1.5 + 3.0 * std::exp(-0.2f * (dx*dx+dy*dy));
+      }
+    }
+    for (int y = 0; y < size; y++) {
+      for (int x = 0; x < size; x++) {
+        if (x != 0) {
+          c.DrawPointLine(
+              5 * (x - 1) + 3 * (y - 0), 90 - 5 * (y - 0) - 5 * ys[y][x - 1],
+              5 * (x - 0) + 3 * (y - 0), 90 - 5 * (y - 0) - 5 * ys[y][x]);
+        }
+        if (y != 0) {
+          c.DrawPointLine(
+              5 * (x - 0) + 3 * (y - 1), 90 - 5 * (y - 1) - 5 * ys[y - 1][x],
+              5 * (x - 0) + 3 * (y - 0), 90 - 5 * (y - 0) - 5 * ys[y][x]);
+        }
+      }
+    }
+
+    return ElementFrom(std::move(c));
+  });
+
+
+  int selected_tab = 0;
+  auto tab = Container::Tab({
+      renderer_line_braille,
+      renderer_line_block,
+      renderer_circle_braille,
+      renderer_circle_block,
+      renderer_circle_filled_braille,
+      renderer_circle_filled_block,
+      renderer_ellipse_braille,
+      renderer_ellipse_block,
+      renderer_ellipse_filled_braille,
+      renderer_ellipse_filled_block,
+
+      renderer_plot_1,
+      renderer_plot_2,
+      renderer_plot_3,
+
+      renderer_text,
+  }, &selected_tab);
+
+  // This capture the last mouse position.
+  auto tab_with_mouse = CatchEvent(tab, [&](Event e) {
+    if (e.is_mouse()) {
+      mouse_x = (e.mouse().x - 1) * 2;
+      mouse_y = (e.mouse().y - 1) * 4;
+    }
+    return false;
+  });
+
+  std::vector<std::string> tab_titles = {
+      "line (braille)",
+      "line (block)",
+      "circle (braille)",
+      "circle (block)",
+      "circle filled (braille)",
+      "circle filled (block)",
+      "ellipse (braille)",
+      "ellipse (block)",
+      "ellipse filled (braille)",
+      "ellipse filled (block)",
+      "plot_1 simple",
+      "plot_2 filled",
+      "plot_3 3D",
+      "text",
+  };
+  auto tab_toggle = Menu(&tab_titles, &selected_tab);
+
+  auto component = Container::Horizontal({
+      tab_with_mouse,
+      tab_toggle,
+  });
+
+  // Add some separator to decorate the whole component:
+  auto component_renderer = Renderer(component, [&] {
+    return hbox({
+               tab_with_mouse->Render(),
+               separator(),
+               tab_toggle->Render(),
+           }) |
+           border;
+  });
+
+  auto screen = ScreenInteractive::FitComponent();
+  screen.Loop(component_renderer);
+
+  return 0;
+}
+
+// Copyright 2021 Arthur Sonzogni. All rights reserved.
+// Use of this source code is governed by the MIT license that can be found in
+// the LICENSED file.

examples/component/focus.cpp

@@ -37,8 +37,8 @@ int main(int argc, const char* argv[]) {
   float focus_x = 0.0f;
   float focus_y = 0.0f;
 
-  auto slider_x = Slider("x", &focus_x, 0.f, 1.f, 0.05f);
-  auto slider_y = Slider("y", &focus_y, 0.f, 1.f, 0.05f);
+  auto slider_x = Slider("x", &focus_x, 0.f, 1.f, 0.01f);
+  auto slider_y = Slider("y", &focus_y, 0.f, 1.f, 0.01f);
 
   auto renderer = Renderer(
       Container::Vertical({

examples/component/homescreen.cpp

@@ -406,8 +406,7 @@ int main(int argc, const char* argv[]) {
                    make_box(6, 3),
                }),
            }) |
-           // vscroll_indicator | yflex;
-           yflex | vscroll_indicator;
+           vscroll_indicator | yframe | flex;
   });
 
   auto paragraph_renderer_right = Renderer([] {

examples/dom/CMakeLists.txt

@@ -7,11 +7,11 @@ example(color_info_palette256)
 example(color_truecolor_HSV)
 example(color_truecolor_RGB)
 example(dbox)
+example(canvas)
 example(gauge)
 example(graph)
 example(gridbox)
 example(hflow)
-example(vflow)
 example(html_like)
 example(package_manager)
 example(paragraph)
@@ -28,4 +28,5 @@ example(style_inverted)
 example(style_underlined)
 example(table)
 example(vbox_hbox)
+example(vflow)
 example(window)

examples/dom/canvas.cpp

@@ -0,0 +1,50 @@
+#include <stddef.h>                // for size_t
+#include <stdio.h>                 // for getchar
+#include <ftxui/dom/elements.hpp>  // for operator|, size, Element, text, hcenter, Decorator, Fit, WIDTH, hflow, window, EQUAL, GREATER_THAN, HEIGHT, bold, border, dim, LESS_THAN
+#include <ftxui/screen/screen.hpp>  // for Full, Screen
+#include <memory>                   // for allocator, shared_ptr
+#include <string>  // for operator+, to_string, char_traits, string
+
+#include "ftxui/dom/flexbox_config.hpp"  // for ftxui
+#include "ftxui/dom/node.hpp"            // for Render
+
+#include <cmath>
+int main(int argc, const char* argv[]) {
+  using namespace ftxui;
+
+  auto canvas = Canvas(100, 100);
+
+  canvas.DrawText(0, 0, "This is a canvas", [](Pixel& p) -> void {
+    p.foreground_color = Color::Red;
+    p.underlined = true;
+  });
+
+  // Triangle:
+  canvas.DrawPointLine(10, 10, 80, 10, Color::Red);
+  canvas.DrawPointLine(80, 10, 80, 40, Color::Blue);
+  canvas.DrawPointLine(80, 40, 10, 10, Color::Green);
+
+  // Circle, not filled and filled:
+  canvas.DrawPointCircle(30, 50, 20);
+  canvas.DrawPointCircleFilled(40, 40, 10);
+
+  // Plot a function:
+  std::vector<int> ys(100);
+  for (int x = 0; x < 100; x++)
+    ys[x] = 80 + 20 * cos(x * 0.2);
+  for (int x = 0; x < 99; x++) 
+    canvas.DrawPointLine(x, ys[x], x + 1, ys[x + 1], Color::Red);
+
+  auto document = ElementFrom(&canvas) | border;
+
+  auto screen = Screen::Create(Dimension::Fit(document));
+  Render(screen, document);
+  screen.Print();
+  getchar();
+
+  return 0;
+}
+
+// Copyright 2020 Arthur Sonzogni. All rights reserved.
+// Use of this source code is governed by the MIT license that can be found in
+// the LICENSE file.

examples/dom/flexbox.cpp

@@ -0,0 +1,38 @@
+#include <stddef.h>                // for size_t
+#include <stdio.h>                 // for getchar
+#include <ftxui/dom/elements.hpp>  // for operator|, size, Element, text, hcenter, Decorator, Fit, WIDTH, hflow, window, EQUAL, GREATER_THAN, HEIGHT, bold, border, dim, LESS_THAN
+#include <ftxui/screen/screen.hpp>  // for Full, Screen
+#include <memory>                   // for allocator, shared_ptr
+#include <string>  // for operator+, to_string, char_traits, string
+
+#include "ftxui/dom/flexbox_config.hpp"  // for ftxui
+#include "ftxui/dom/node.hpp"            // for Render
+
+int main(int argc, const char* argv[]) {
+  using namespace ftxui;
+
+  auto image = Canvas(100, 100);
+
+  auto document = vbox({
+    make_box("header"),
+    hbox({
+      make_box("left side"),
+      make_box("center") | flex,
+      make_box("right side"),
+    }) | flex,
+    make_box("footer")
+  });
+
+  //auto screen = Screen::Create(Dimension::Full(), Dimension::Fit(document));
+  //auto screen = Screen::Create(Dimension::Fit(document));
+  auto screen = Screen::Create(Dimension::Full());
+  Render(screen, document);
+  screen.Print();
+  getchar();
+
+  return 0;
+}
+
+// Copyright 2020 Arthur Sonzogni. All rights reserved.
+// Use of this source code is governed by the MIT license that can be found in
+// the LICENSE file.

examples/index.html

@@ -71,7 +71,10 @@
       postRun: [],
       onRuntimeInitialized: () => {},
     };
-    document.querySelector("#example_script").src = example + '.js';
+
+    const words = example.split('/')
+    words[1] = "ftxui_example_" + words[1] + ".js"
+    document.querySelector("#example_script").src = words.join('/');
   </script>
 
   <style>