More robust saturation mechanism

src/ftxui/component/screen_interactive.cpp

@@ -837,7 +837,7 @@ bool ScreenInteractive::HandleSelection(Event event) {
     return false;
   }
 
-  if (mouse.motion == Mouse::Pressed) {
+  if(mouse.motion == Mouse::Pressed) {
       selection_pending_ = CaptureMouse();
       if (!selection_pending_) {
         return false;
@@ -849,25 +849,19 @@ bool ScreenInteractive::HandleSelection(Event event) {
       selection_box_.y_max = mouse.y;
       return true;
   }
-
-  if (!selection_pending_) {
-    return false;
-  }
-
-  if (mouse.motion == Mouse::Moved) {
+  else if((mouse.motion == Mouse::Moved) && (selection_pending_)) {
       selection_box_.x_max = mouse.x;
       selection_box_.y_max = mouse.y;
       return true;
   }
-
-  if (mouse.motion != Mouse::Released) {
-    return false;
-  }
-
+  else if((mouse.motion == Mouse::Released) && (selection_pending_)) {
       selection_box_.x_max = mouse.x;
       selection_box_.y_max = mouse.y;
       selection_pending_ = nullptr;
       return true;
+  }
+
+  return false;
 }
 
 // private

src/ftxui/dom/hbox.cpp

@@ -72,16 +72,16 @@ class HBox : public Node {
       return;
     }
 
-    const bool xmin_satured =
+    const bool xmin_saturated =
         selection.y_min < box_.y_min || selection.x_min < box_.x_min;
-    const bool xmax_satured =
+    const bool xmax_saturated =
         selection.y_max > box_.y_max || selection.x_max > box_.x_max;
 
-    if (xmin_satured) {
-      selection.x_min = box_.x_min;
+    if (xmin_saturated) {
+      selection.x_min = std::min(box_.x_min, selection.x_min);
     }
-    if (xmax_satured) {
-      selection.x_max = box_.x_max;
+    if (xmax_saturated) {
+      selection.x_max = std::max(box_.x_max, selection.x_max);
     }
 
     for (auto& child : children_) {

src/ftxui/dom/node.cpp

@@ -94,7 +94,21 @@ void Render(Screen& screen, Node* node, Box selection) {
 
   // Step 3: Selection
   std::vector<Box> selected;
-  node->Selection(selection, &selected);
+
+  Box selectionCleaned = selection;
+  if(selection.x_min > selection.x_max)
+  {
+    selectionCleaned.x_min = selection.x_max;
+    selectionCleaned.x_max = selection.x_min;
+  }
+  
+  if(selection.y_min > selection.y_max)
+  {
+    selectionCleaned.y_min = selection.y_max;
+    selectionCleaned.y_max = selection.y_min;
+  }
+
+  node->Selection(selectionCleaned, &selected);
 
   // Step 4: Draw the element.
   screen.stencil = box;

src/ftxui/dom/text.cpp

@@ -33,13 +33,13 @@ class Text : public Node {
       return;
     }
 
-    const bool xmin_satured =
+    const bool xmin_saturated =
         selection.y_min < box_.y_min || selection.x_min < box_.x_min;
-    const bool xmax_satured =
+    const bool xmax_saturated =
         selection.y_max > box_.y_max || selection.x_max > box_.x_max;
 
-    selection_start_ = xmin_satured ? box_.x_min : selection.x_min;
-    selection_end_ = xmax_satured ? box_.x_max : selection.x_max;
+    selection_start_ = xmin_saturated ? box_.x_min : selection.x_min;
+    selection_end_ = xmax_saturated ? box_.x_max : selection.x_max;
 
     has_selection = true;
 
@@ -67,19 +67,16 @@ class Text : public Node {
       }
       screen.PixelAt(x, y).character = cell;
 
-      ++x;
-    }
-
-    if (!has_selection) {
-      return;
-    }
-
-    // Invert the selection
-    for(int x = selection_start_; x <= selection_end_; x++) {
+      if (has_selection) {
+        if((x >= selection_start_) && (x <= selection_end_)) {
           screen.PixelAt(x, y).inverted = true;
         }
       }
 
+      ++x;
+    }
+  }
+
  private:
   std::string text_;
   bool has_selection = false;

src/ftxui/dom/vbox.cpp

@@ -72,15 +72,16 @@ class VBox : public Node {
       return;
     }
 
-    const bool ymin_satured =
+    const bool ymin_saturated =
       selection.x_min < box_.x_min || selection.y_min < box_.y_min;
-    const bool ymax_satured =
+    const bool ymax_saturated =
       selection.x_max > box_.x_max || selection.y_max > box_.y_max;
-    if (ymin_satured) {
-      selection.y_min = box_.y_min;
+
+    if (ymin_saturated) {
+      selection.y_min = std::min(box_.y_min, selection.y_min);
     }
-    if (ymax_satured) {
-      selection.y_max = box_.y_max;
+    if (ymax_saturated) {
+      selection.y_max = std::max(box_.y_max, selection.y_max);
     }
     
     for (auto& child : children_) {