Fix + support for indpendant styles.

examples/component/gallery.cpp

@@ -97,7 +97,25 @@ int main() {
   });
   sliders = Wrap("Slider", sliders);
 
-  // -- Layout -----------------------------------------------------------------
+  // A large text:
+  auto lorel_ipsum = Renderer([] {
+    return vbox({
+        text("Lorem ipsum dolor sit amet, consectetur adipiscing elit. "),
+        text("Sed do eiusmod tempor incididunt ut labore et dolore magna "
+             "aliqua. "),
+        text("Ut enim ad minim veniam, quis nostrud exercitation ullamco "
+             "laboris nisi ut aliquip ex ea commodo consequat. "),
+        text("Duis aute irure dolor in reprehenderit in voluptate velit esse "
+             "cillum dolore eu fugiat nulla pariatur. "),
+        text("Excepteur sint occaecat cupidatat non proident, sunt in culpa "
+             "qui officia deserunt mollit anim id est laborum. "),
+
+    });
+  });
+  lorel_ipsum = Wrap("Lorel Ipsum", lorel_ipsum);
+
+  // -- Layout
+  // -----------------------------------------------------------------
   auto layout = Container::Vertical({
       menu,
       toggle,
@@ -106,6 +124,7 @@ int main() {
       input,
       sliders,
       button,
+      lorel_ipsum,
   });
 
   auto component = Renderer(layout, [&] {
@@ -123,6 +142,8 @@ int main() {
                sliders->Render(),
                separator(),
                button->Render(),
+               separator(),
+               lorel_ipsum->Render(),
            }) |
            xflex | size(WIDTH, GREATER_THAN, 40) | border;
   });

examples/component/homescreen.cpp

@@ -424,7 +424,7 @@ int main() {
   auto paragraph_renderer_left = Renderer([&] {
     std::string str =
         "Lorem Ipsum is simply dummy text of the printing and typesetting "
-        "industry. Lorem Ipsum has been the industry's standard dummy text "
+        "industry.\nLorem Ipsum has been the industry's standard dummy text "
         "ever since the 1500s, when an unknown printer took a galley of type "
         "and scrambled it to make a type specimen book.";
     return vbox({

examples/component/selection.cpp

@@ -0,0 +1,89 @@
+// 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.
+#include <string>  // for char_traits, operator+, string, basic_string
+
+#include "ftxui/component/component.hpp"       // for Input, Renderer, Vertical
+#include "ftxui/component/component_base.hpp"  // for ComponentBase
+#include "ftxui/component/component_options.hpp"  // for InputOption
+#include "ftxui/component/screen_interactive.hpp"  // for Component, ScreenInteractive
+#include "ftxui/dom/elements.hpp"  // for text, hbox, separator, Element, operator|, vbox, border
+#include "ftxui/util/ref.hpp"  // for Ref
+
+using namespace ftxui;
+
+Element LoremIpsum() {
+  return vbox({
+      text("Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do "
+           "eiusmod tempor incididunt ut labore et dolore magna aliqua."),
+      text("Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris "
+           "nisi ut aliquip ex ea commodo consequat."),
+      text("Duis aute irure dolor in reprehenderit in voluptate velit esse "
+           "cillum dolore eu fugiat nulla pariatur."),
+  });
+}
+
+int main() {
+  auto screen = ScreenInteractive::TerminalOutput();
+
+  auto quit =
+      Button("Quit", screen.ExitLoopClosure(), ButtonOption::Animated());
+
+  int selection_change_counter = 0;
+  std::string selection_content = "";
+  screen.SelectionOnChange([&] {
+    selection_change_counter++;
+    selection_content = screen.SelectionAsString();
+  });
+
+  // The components:
+  auto renderer = Renderer(quit, [&] {
+    return vbox({
+        text("Select changed: " + std::to_string(selection_change_counter) +
+             " times"),
+        text("Currently selected: "),
+        paragraph(selection_content) | frame | border | xflex |
+            size(HEIGHT, EQUAL, 10),
+        window(text("Horizontal split"), hbox({
+                                             LoremIpsum(),
+                                             separator(),
+                                             LoremIpsum(),
+                                             separator(),
+                                             LoremIpsum(),
+                                         })),
+        window(text("Vertical split"), vbox({
+                                           LoremIpsum(),
+                                           separator(),
+                                           LoremIpsum(),
+                                           separator(),
+                                           LoremIpsum(),
+                                       })),
+        window(text("Grid split"),
+               vbox({
+                   hbox({
+                       LoremIpsum(),
+                       separator(),
+                       LoremIpsum()                                   //
+                           | selectionBackgroundColor(Color::Yellow)  //
+                           | selectionColor(Color::Black)             //
+                           | selectionStyleReset,
+                       separator(),
+                       LoremIpsum() | selectionColor(Color::Blue),
+                   }),
+                   separator(),
+                   hbox({
+                       LoremIpsum() | selectionColor(Color::Red),
+                       separator(),
+                       LoremIpsum() | selectionStyle([](Pixel& pixel) {
+                         pixel.underlined_double = true;
+                       }),
+                       separator(),
+                       LoremIpsum(),
+                   }),
+               })),
+        quit->Render(),
+    });
+  });
+
+  screen.Loop(renderer);
+}

include/ftxui/component/screen_interactive.hpp

@@ -15,8 +15,8 @@
 #include "ftxui/component/animation.hpp"       // for TimePoint
 #include "ftxui/component/captured_mouse.hpp"  // for CapturedMouse
 #include "ftxui/component/event.hpp"           // for Event
-#include "ftxui/dom/selection.hpp"             // for SelectionOption
 #include "ftxui/component/task.hpp"            // for Task, Closure
+#include "ftxui/dom/selection.hpp"             // for SelectionOption
 #include "ftxui/screen/screen.hpp"             // for Screen
 
 namespace ftxui {
@@ -70,7 +70,8 @@ class ScreenInteractive : public Screen {
   void ForceHandleCtrlZ(bool force);
 
   // Selection API.
-  std::string GetSelectedContent(Component component);
+  std::string SelectionAsString();
+  void SelectionOnChange(std::function<void()> callback);
 
  private:
   void ExitNow();
@@ -86,7 +87,7 @@ class ScreenInteractive : public Screen {
   void RunOnceBlocking(Component component);
 
   void HandleTask(Component component, Task& task);
-  bool HandleSelection(Event event);
+  bool HandleSelection(bool handled, Event event);
   void RefreshSelection();
   void Draw(Component component);
   void ResetCursorPosition();
@@ -137,11 +138,19 @@ class ScreenInteractive : public Screen {
 
   // Selection API:
   CapturedMouse selection_pending_;
-  int selection_start_x_ = 0;
+  struct SelectionData {
-  int selection_start_y_ = 0;
+    int start_x = -1;
-  int selection_end_x_ = 0;
+    int start_y = -1;
-  int selection_end_y_ = 0;
+    int end_x = -2;
-  bool selection_changed = false;
+    int end_y = -2;
+    bool empty = true;
+    bool operator==(const SelectionData& other) const;
+    bool operator!=(const SelectionData& other) const;
+  };
+  SelectionData selection_data_;
+  SelectionData selection_data_previous_;
+  std::unique_ptr<Selection> selection_;
+  std::function<void()> selection_on_change_;
 
   friend class Loop;
 

include/ftxui/dom/node.hpp

@@ -68,7 +68,9 @@ class Node {
 void Render(Screen& screen, const Element& element);
 void Render(Screen& screen, Node* node);
 void Render(Screen& screen, Node* node, Selection& selection);
-std::string GetNodeSelectedContent(Screen& screen, Node* node, Selection& selection);
+std::string GetNodeSelectedContent(Screen& screen,
+                                   Node* node,
+                                   Selection& selection);
 
 }  // namespace ftxui
 

include/ftxui/dom/selection.hpp

@@ -7,6 +7,7 @@
 
 #include <functional>
 
+#include <sstream>
 #include "ftxui/screen/box.hpp"    // for Box
 #include "ftxui/screen/pixel.hpp"  // for Pixel
 
@@ -15,19 +16,33 @@ namespace ftxui {
 /// @brief Represent a selection in the terminal.
 class Selection {
  public:
+  Selection();  // Empty selection.
   Selection(int start_x, int start_y, int end_x, int end_y);
+
   const Box& GetBox() const;
 
   Selection SaturateHorizontal(Box box);
   Selection SaturateVertical(Box box);
+  bool IsEmpty() const { return empty_; }
+
+  void AddPart(const std::string& part, int y, int left, int right);
+  std::string GetParts() { return parts_.str(); }
 
  private:
-  Selection* const parent_ = nullptr;
+  Selection(int start_x, int start_y, int end_x, int end_y, Selection* parent);
-  const int start_x_;
+
-  const int start_y_;
+  Selection* const parent_ = this;
-  const int end_x_;
+  const bool empty_ = true;
-  const int end_y_;
+  const int start_x_ = 0;
-  const Box box_;
+  const int start_y_ = 0;
+  const int end_x_ = 0;
+  const int end_y_ = 0;
+  const Box box_ = {};
+  std::stringstream parts_;
+
+  // The position of the last inserted part.
+  int x_ = 0;
+  int y_ = 0;
 };
 
 }  // namespace ftxui

src/ftxui/component/screen_interactive.cpp

@@ -577,11 +577,15 @@ void ScreenInteractive::ForceHandleCtrlZ(bool force) {
 }
 
 /// @brief Returns the content of the current selection
-std::string ScreenInteractive::GetSelectedContent(Component component) {
+std::string ScreenInteractive::SelectionAsString() {
-  Selection selection(selection_start_x_, selection_start_y_,  //
+  if (!selection_) {
-                      selection_end_x_, selection_end_y_);
+    return "";
+  }
+  return selection_->GetParts();
+}
 
-  return GetNodeSelectedContent(*this, component->Render().get(), selection);
+void ScreenInteractive::SelectionOnChange(std::function<void()> callback) {
+  selection_on_change_ = std::move(callback);
 }
 
 /// @brief Return the currently active screen, or null if none.
@@ -759,6 +763,14 @@ void ScreenInteractive::RunOnce(Component component) {
     ExecuteSignalHandlers();
   }
   Draw(std::move(component));
+
+  if (selection_data_previous_ != selection_data_) {
+    selection_data_previous_ = selection_data_;
+    if (selection_on_change_) {
+      selection_on_change_();
+      Post(Event::Custom);
+    }
+  }
 }
 
 // private
@@ -791,7 +803,7 @@ void ScreenInteractive::HandleTask(Component component, Task& task) {
 
       bool handled = component->OnEvent(arg);
 
-      handled = handled || HandleSelection(arg);
+      handled = HandleSelection(handled, arg);
 
       if (arg == Event::CtrlC && (!handled || force_handle_ctrl_c_)) {
         RecordSignal(SIGABRT);
@@ -835,8 +847,13 @@ void ScreenInteractive::HandleTask(Component component, Task& task) {
 }
 
 // private
-bool ScreenInteractive::HandleSelection(Event event) {
+bool ScreenInteractive::HandleSelection(bool handled, Event event) {
-  selection_changed = false;
+  if (handled) {
+    selection_pending_ = nullptr;
+    selection_data_.empty = false;
+    selection_ = nullptr;
+    return true;
+  }
 
   if (!event.is_mouse()) {
     return false;
@@ -849,12 +866,11 @@ bool ScreenInteractive::HandleSelection(Event event) {
 
   if (mouse.motion == Mouse::Pressed) {
     selection_pending_ = CaptureMouse();
-    selection_start_x_ = mouse.x;
+    selection_data_.start_x = mouse.x;
-    selection_start_y_ = mouse.y;
+    selection_data_.start_y = mouse.y;
-    selection_end_x_ = mouse.x;
+    selection_data_.end_x = mouse.x;
-    selection_end_y_ = mouse.y;
+    selection_data_.end_y = mouse.y;
-
+    return false;
-    selection_changed = true;
   }
 
   if (!selection_pending_) {
@@ -862,11 +878,11 @@ bool ScreenInteractive::HandleSelection(Event event) {
   }
 
   if (mouse.motion == Mouse::Moved) {
-    if((mouse.x != selection_end_x_) || (mouse.y != selection_end_y_)) {
+    if ((mouse.x != selection_data_.end_x) ||
-      selection_end_x_ = mouse.x;
+        (mouse.y != selection_data_.end_y)) {
-      selection_end_y_ = mouse.y;
+      selection_data_.end_x = mouse.x;
-
+      selection_data_.end_y = mouse.y;
-      selection_changed = true;
+      selection_data_.empty = false;
     }
 
     return true;
@@ -874,10 +890,9 @@ bool ScreenInteractive::HandleSelection(Event event) {
 
   if (mouse.motion == Mouse::Released) {
     selection_pending_ = nullptr;
-    selection_end_x_ = mouse.x;
+    selection_data_.end_x = mouse.x;
-    selection_end_y_ = mouse.y;
+    selection_data_.end_y = mouse.y;
-
+    selection_data_.empty = false;
-    selection_changed = true;
     return true;
   }
 
@@ -959,9 +974,12 @@ void ScreenInteractive::Draw(Component component) {
 #endif
   previous_frame_resized_ = resized;
 
-  Selection selection(selection_start_x_, selection_start_y_,  //
+  selection_ = selection_data_.empty
-                      selection_end_x_, selection_end_y_);
+                   ? std::make_unique<Selection>()
-  Render(*this, document.get(), selection);
+                   : std::make_unique<Selection>(
+                         selection_data_.start_x, selection_data_.start_y,  //
+                         selection_data_.end_x, selection_data_.end_y);
+  Render(*this, document.get(), *selection_);
 
   // Set cursor position for user using tools to insert CJK characters.
   {
@@ -1050,4 +1068,21 @@ void ScreenInteractive::Signal(int signal) {
 #endif
 }
 
+bool ScreenInteractive::SelectionData::operator==(
+    const ScreenInteractive::SelectionData& other) const {
+  if (empty && other.empty) {
+    return true;
+  }
+  if (empty || other.empty) {
+    return false;
+  }
+  return start_x == other.start_x && start_y == other.start_y &&
+         end_x == other.end_x && end_y == other.end_y;
+}
+
+bool ScreenInteractive::SelectionData::operator!=(
+    const ScreenInteractive::SelectionData& other) const {
+  return !(*this == other);
+}
+
 }  // namespace ftxui.

src/ftxui/dom/node.cpp

@@ -58,7 +58,6 @@ void Node::Check(Status* status) {
 }
 
 std::string Node::GetSelectedContent(Selection& selection) {
-
   std::string content;
 
   for (auto& child : children_) {
@@ -71,14 +70,14 @@ std::string Node::GetSelectedContent(Selection& selection) {
 /// @brief Display an element on a ftxui::Screen.
 /// @ingroup dom
 void Render(Screen& screen, const Element& element) {
-  Selection selection(0, 0, -1, -1);
+  Selection selection;
   Render(screen, element.get(), selection);
 }
 
 /// @brief Display an element on a ftxui::Screen.
 /// @ingroup dom
 void Render(Screen& screen, Node* node) {
-  Selection selection(0, 0, -1, -1);
+  Selection selection;
   Render(screen, node, selection);
 }
 
@@ -106,7 +105,9 @@ void Render(Screen& screen, Node* node, Selection& selection) {
   }
 
   // Step 3: Selection
-  node->Select(selection);
+  if (!selection.IsEmpty()) {
+    node->Select(selection);
+  }
 
   // Step 4: Draw the element.
   screen.stencil = box;
@@ -116,8 +117,9 @@ void Render(Screen& screen, Node* node, Selection& selection) {
   screen.ApplyShader();
 }
 
-std::string GetNodeSelectedContent(Screen& screen, Node* node, Selection& selection) {
+std::string GetNodeSelectedContent(Screen& screen,
-
+                                   Node* node,
+                                   Selection& selection) {
   Box box;
   box.x_min = 0;
   box.y_min = 0;

src/ftxui/dom/paragraph.cpp

@@ -20,6 +20,18 @@ Elements Split(const std::string& the_text) {
   }
   return output;
 }
+
+Element Split(const std::string& paragraph,
+              std::function<Element(std::string)> f) {
+  Elements output;
+  std::stringstream ss(paragraph);
+  std::string line;
+  while (std::getline(ss, line, '\n')) {
+    output.push_back(f(line));
+  }
+  return vbox(std::move(output));
+}
+
 }  // namespace
 
 /// @brief Return an element drawing the paragraph on multiple lines.
@@ -34,18 +46,22 @@ Element paragraph(const std::string& the_text) {
 /// @ingroup dom
 /// @see flexbox.
 Element paragraphAlignLeft(const std::string& the_text) {
-  static const auto config = FlexboxConfig().SetGap(1, 0);
+  return Split(the_text, [](const std::string& line) {
-  return flexbox(Split(the_text), config);
+    static const auto config = FlexboxConfig().SetGap(1, 0);
-}
+    return flexbox(Split(line), config);
+  });
+};
 
 /// @brief Return an element drawing the paragraph on multiple lines, aligned on
 /// the right.
 /// @ingroup dom
 /// @see flexbox.
 Element paragraphAlignRight(const std::string& the_text) {
-  static const auto config =
+  return Split(the_text, [](const std::string& line) {
-      FlexboxConfig().SetGap(1, 0).Set(FlexboxConfig::JustifyContent::FlexEnd);
+    static const auto config = FlexboxConfig().SetGap(1, 0).Set(
-  return flexbox(Split(the_text), config);
+        FlexboxConfig::JustifyContent::FlexEnd);
+    return flexbox(Split(line), config);
+  });
 }
 
 /// @brief Return an element drawing the paragraph on multiple lines, aligned on
@@ -53,9 +69,11 @@ Element paragraphAlignRight(const std::string& the_text) {
 /// @ingroup dom
 /// @see flexbox.
 Element paragraphAlignCenter(const std::string& the_text) {
-  static const auto config =
+  return Split(the_text, [](const std::string& line) {
-      FlexboxConfig().SetGap(1, 0).Set(FlexboxConfig::JustifyContent::Center);
+    static const auto config =
-  return flexbox(Split(the_text), config);
+        FlexboxConfig().SetGap(1, 0).Set(FlexboxConfig::JustifyContent::Center);
+    return flexbox(Split(line), config);
+  });
 }
 
 /// @brief Return an element drawing the paragraph on multiple lines, aligned
@@ -64,11 +82,13 @@ Element paragraphAlignCenter(const std::string& the_text) {
 /// @ingroup dom
 /// @see flexbox.
 Element paragraphAlignJustify(const std::string& the_text) {
-  static const auto config = FlexboxConfig().SetGap(1, 0).Set(
+  return Split(the_text, [](const std::string& line) {
-      FlexboxConfig::JustifyContent::SpaceBetween);
+    static const auto config = FlexboxConfig().SetGap(1, 0).Set(
-  Elements words = Split(the_text);
+        FlexboxConfig::JustifyContent::SpaceBetween);
-  words.push_back(text("") | xflex);
+    Elements words = Split(line);
-  return flexbox(std::move(words), config);
+    words.push_back(text("") | xflex);
+    return flexbox(std::move(words), config);
+  });
 }
 
 }  // namespace ftxui

src/ftxui/dom/selection.cpp

@@ -21,6 +21,9 @@ class Unselectable : public NodeDecorator {
 };
 }  // namespace
 
+/// @brief Create an empty selection.
+Selection::Selection() : empty_(true) {}
+
 /// @brief Create a selection.
 /// @param start_x The x coordinate of the start of the selection.
 /// @param start_y The y coordinate of the start of the selection.
@@ -36,7 +39,26 @@ Selection::Selection(int start_x, int start_y, int end_x, int end_y)
           std::max(start_x, end_x),
           std::min(start_y, end_y),
           std::max(start_y, end_y),
-      } {}
+      },
+      empty_(false) {}
+
+Selection::Selection(int start_x,
+                     int start_y,
+                     int end_x,
+                     int end_y,
+                     Selection* parent)
+    : start_x_(start_x),
+      start_y_(start_y),
+      end_x_(end_x),
+      end_y_(end_y),
+      box_{
+          std::min(start_x, end_x),
+          std::max(start_x, end_x),
+          std::min(start_y, end_y),
+          std::max(start_y, end_y),
+      },
+      parent_(parent),
+      empty_(false) {}
 
 /// @brief Get the box of the selection.
 /// @return The box of the selection.
@@ -77,7 +99,7 @@ Selection Selection::SaturateHorizontal(Box box) {
       end_y = box.y_min;
     }
   }
-  return Selection(start_x, start_y, end_x, end_y);
+  return Selection(start_x, start_y, end_x, end_y, parent_);
 }
 
 /// @brief Saturate the selection to be inside the box.
@@ -114,7 +136,33 @@ Selection Selection::SaturateVertical(Box box) {
       end_y = box.y_min;
     }
   }
-  return Selection(start_x, start_y, end_x, end_y);
+  return Selection(start_x, start_y, end_x, end_y, parent_);
+}
+
+void Selection::AddPart(const std::string& part, int y, int left, int right) {
+  if (parent_ != this) {
+    return parent_->AddPart(part, y, left, right);
+  }
+  [&] {
+    if (parts_.str().empty()) {
+      parts_ << "[" + part + "]";
+      return;
+    }
+
+    if (y_ != y) {
+      parts_ << '\n' << part;
+      return;
+    }
+
+    if (x_ == left + 1) {
+      parts_ << "|" << part;
+      return;
+    }
+
+    parts_ << "-" << part;
+  }();
+  y_ = y;
+  x_ = right;
 }
 
 }  // namespace ftxui

src/ftxui/dom/selection_style.cpp

@@ -0,0 +1,89 @@
+// Copyright 2024 Arthur Sonzogni. All rights reserved.
+// Use of this source code is governed by the MIT license that can be found in
+// the LICENSE file.
+#include <memory>   // for make_shared
+#include <utility>  // for move
+
+#include "ftxui/dom/elements.hpp"  // for Element, Decorator, bgcolor, color
+#include "ftxui/dom/node_decorator.hpp"  // for NodeDecorator
+#include "ftxui/screen/box.hpp"          // for Box
+#include "ftxui/screen/color.hpp"        // for Color
+#include "ftxui/screen/screen.hpp"       // for Pixel, Screen
+
+namespace ftxui {
+
+namespace {
+
+class SelectionStyleReset : public NodeDecorator {
+ public:
+  SelectionStyleReset(Element child) : NodeDecorator(std::move(child)) {}
+
+  void Render(Screen& screen) final {
+    auto old_style = screen.GetSelectionStyle();
+    screen.SetSelectionStyle([](Pixel& pixel) {});
+    NodeDecorator::Render(screen);
+    screen.SetSelectionStyle(old_style);
+  }
+};
+
+class SelectionStyle : public NodeDecorator {
+ public:
+  SelectionStyle(Element child, std::function<void(Pixel&)> style)
+      : NodeDecorator(std::move(child)), style_(style) {}
+
+  void Render(Screen& screen) final {
+    auto old_style = screen.GetSelectionStyle();
+    auto new_style = [&, old_style](Pixel& pixel) {
+      old_style(pixel);
+      style_(pixel);
+    };
+    screen.SetSelectionStyle(new_style);
+    NodeDecorator::Render(screen);
+    screen.SetSelectionStyle(old_style);
+  }
+
+  std::function<void(Pixel&)> style_;
+};
+
+}  // namespace
+
+/// @brief Reset the selection style of an element.
+/// @param child The input element.
+/// @return The output element with the selection style reset.
+Element selectionStyleReset(Element child) {
+  return std::make_shared<SelectionStyleReset>(std::move(child));
+}
+
+/// @brief Set the background color of an element when selected.
+/// Note that the style is applied on top of the existing style.
+Decorator selectionBackgroundColor(Color foreground) {
+  return selectionStyle([foreground](Pixel& pixel) {  //
+    pixel.background_color = foreground;
+  });
+}
+
+/// @brief Set the foreground color of an element when selected.
+/// Note that the style is applied on top of the existing style.
+Decorator selectionForegroundColor(Color foreground) {
+  return selectionStyle([foreground](Pixel& pixel) {  //
+    pixel.foreground_color = foreground;
+  });
+}
+
+/// @brief Set the color of an element when selected.
+/// @param foreground The color to be applied.
+/// Note that the style is applied on top of the existing style.
+Decorator selectionColor(Color foreground) {
+  return selectionForegroundColor(foreground);
+}
+
+/// @brief Set the style of an element when selected.
+/// @param style The style to be applied.
+/// Note that the style is applied on top of the existing style.
+Decorator selectionStyle(std::function<void(Pixel&)> style) {
+  return [style](Element child) -> Element {
+    return std::make_shared<SelectionStyle>(std::move(child), style);
+  };
+}
+
+}  // namespace ftxui

src/ftxui/dom/selection_test.cpp

@@ -40,56 +40,118 @@ Event MouseReleased(int x, int y) {
   mouse.y = y;
   return Event::Mouse("jjj", mouse);
 }
+
+Event MouseMove(int x, int y) {
+  Mouse mouse;
+  mouse.button = Mouse::Left;
+  mouse.motion = Mouse::Moved;
+  mouse.shift = false;
+  mouse.meta = false;
+  mouse.control = false;
+  mouse.x = x;
+  mouse.y = y;
+  return Event::Mouse("jjj", mouse);
+}
+
 }  // namespace
 
 TEST(SelectionTest, DefaultSelection) {
   auto component = Renderer([&] { return text("Lorem ipsum dolor"); });
-
   auto screen = ScreenInteractive::FixedSize(20, 1);
-
+  EXPECT_EQ(screen.SelectionAsString(), "");
   Loop loop(&screen, component);
-
-  loop.RunOnce();
   screen.PostEvent(MousePressed(3, 1));
-  loop.RunOnce();
   screen.PostEvent(MouseReleased(10, 1));
   loop.RunOnce();
 
-  EXPECT_STREQ(screen.GetSelectedContent(component).c_str(), "rem ipsu");
+  EXPECT_EQ(screen.SelectionAsString(), "rem ipsu");
 }
 
-TEST(SelectionTest, CallbackSelection) {
+TEST(SelectionTest, SelectionOnChange) {
   int selectionChangeCounter = 0;
-
   auto component = Renderer([&] { return text("Lorem ipsum dolor"); });
-
   auto screen = ScreenInteractive::FixedSize(20, 1);
+  screen.SelectionOnChange([&] { selectionChangeCounter++; });
 
   Loop loop(&screen, component);
-
   loop.RunOnce();
+  EXPECT_EQ(selectionChangeCounter, 0);
+
   screen.PostEvent(MousePressed(3, 1));
   loop.RunOnce();
-  screen.PostEvent(MouseReleased(10, 1));
+  EXPECT_EQ(selectionChangeCounter, 0);
-  loop.RunOnce();
 
+  screen.PostEvent(MouseMove(5, 1));
+  loop.RunOnce();
+  EXPECT_EQ(selectionChangeCounter, 1);
+
+  screen.PostEvent(MouseMove(7, 1));
+  loop.RunOnce();
   EXPECT_EQ(selectionChangeCounter, 2);
 
-  EXPECT_STREQ(screen.GetSelectedContent(component).c_str(), "rem ipsu");
+  screen.PostEvent(MouseReleased(10, 1));
+  loop.RunOnce();
+  EXPECT_EQ(selectionChangeCounter, 3);
+
+  screen.PostEvent(MouseMove(10, 1));
+  loop.RunOnce();
+  EXPECT_EQ(selectionChangeCounter, 3);
+
+  EXPECT_EQ(screen.SelectionAsString(), "rem ipsu");
+}
+
+// Check that submitting multiple mouse events quickly doesn't trigger multiple
+// selection change events.
+TEST(SelectionTest, SelectionOnChangeSquashedEvents) {
+  int selectionChangeCounter = 0;
+  auto component = Renderer([&] { return text("Lorem ipsum dolor"); });
+  auto screen = ScreenInteractive::FixedSize(20, 1);
+  screen.SelectionOnChange([&] { selectionChangeCounter++; });
+
+  Loop loop(&screen, component);
+  loop.RunOnce();
+  EXPECT_EQ(selectionChangeCounter, 0);
+
+  screen.PostEvent(MousePressed(3, 1));
+  screen.PostEvent(MouseMove(5, 1));
+  screen.PostEvent(MouseMove(7, 1));
+  loop.RunOnce();
+  EXPECT_EQ(selectionChangeCounter, 1);
+
+  screen.PostEvent(MouseReleased(10, 1));
+  screen.PostEvent(MouseMove(10, 1));
+  loop.RunOnce();
+  EXPECT_EQ(selectionChangeCounter, 2);
+
+  EXPECT_EQ(screen.SelectionAsString(), "rem ipsu");
 }
 
 TEST(SelectionTest, StyleSelection) {
   int selectionChangeCounter = 0;
 
-  auto component = Renderer([&] { return text("Lorem ipsum dolor"); });
+  auto element = hbox({
+      text("Lorem "),
+      text("ipsum") | selectionColor(Color::Red),
+      text(" dolor"),
+  });
 
   auto screen = ScreenInteractive::FixedSize(20, 1);
-
   Selection selection(2, 0, 9, 0);
 
-  Render(screen, component->Render().get(), selection);
+  Render(screen, element.get(), selection);
+  for (int i = 0; i < 20; i++) {
+    if (i >= 2 && i <= 9) {
+      EXPECT_EQ(screen.PixelAt(i, 0).inverted, true);
+    } else {
+      EXPECT_EQ(screen.PixelAt(i, 0).inverted, false);
+    }
 
-  EXPECT_EQ(screen.ToString(), "Lo\x1B[21mrem ipsu\x1B[24mm dolor   ");
+    if (i >= 6 && i <= 9) {
+      EXPECT_EQ(screen.PixelAt(i, 0).foreground_color, Color::Red);
+    } else {
+      EXPECT_EQ(screen.PixelAt(i, 0).foreground_color, Color::Default);
+    }
+  }
 }
 
 TEST(SelectionTest, VBoxSelection) {

src/ftxui/dom/text.cpp

@@ -3,8 +3,9 @@
 // the LICENSE file.
 #include <algorithm>  // for min
 #include <memory>     // for make_shared
-#include <string>     // for string, wstring
+#include <sstream>
-#include <utility>    // for move
+#include <string>   // for string, wstring
+#include <utility>  // for move
 
 #include "ftxui/dom/deprecated.hpp"   // for text, vtext
 #include "ftxui/dom/elements.hpp"     // for Element, text, vtext
@@ -39,6 +40,19 @@ class Text : public Node {
     has_selection = true;
     selection_start_ = selection_saturated.GetBox().x_min;
     selection_end_ = selection_saturated.GetBox().x_max;
+
+    std::stringstream ss;
+    int x = box_.x_min;
+    for (const auto& cell : Utf8ToGlyphs(text_)) {
+      if (cell == "\n") {
+        continue;
+      }
+      if (selection_start_ <= x && x <= selection_end_) {
+        ss << cell;
+      }
+      x++;
+    }
+    selection.AddPart(ss.str(), box_.y_min, selection_start_, selection_end_);
   }
 
   void Render(Screen& screen) override {
@@ -69,34 +83,11 @@ class Text : public Node {
     }
   }
 
-  std::string GetSelectedContent(Selection& selection) {
-    int x = box_.x_min;
-    std::string selected_text = "";
-
-    if (has_selection == false) {
-      return "";
-    }
-
-    for (const auto& cell : Utf8ToGlyphs(text_)) {
-      if (x > box_.x_max) {
-        break;
-      }
-
-      if ((x >= selection_start_) && (x <= selection_end_)) {
-        selected_text += cell;
-      }
-
-      ++x;
-    }
-
-    return selected_text;
-  }
-
  private:
   std::string text_;
   bool has_selection = false;
   int selection_start_ = 0;
-  int selection_end_ = 10;
+  int selection_end_ = -1;
   std::function<void(Pixel& pixel)> selectionTransform;
 };