Introduce move based focusing

1 files changed, 36 insertions, 0 deletions

diff --git a/src/components/Scrollbar.cpp b/src/components/Scrollbar.cpp
index 76c5c1a..ac713e9 100644
--- a/src/components/Scrollbar.cpp
+++ b/src/components/Scrollbar.cpp
@@ -109,4 +109,40 @@ void Scrollbar::Refresh() {
   elements.push_back(bar);
 }
 
+void Scrollbar::Focus(double XorY){
+  double MTCanvasHeight = status->CanvasHeight - status->ScrollbarWidth;
+  double MTCanvasWidth = status->CanvasWidth - status->ScrollbarWidth;
+  // Check horizontal or vertical and if should scroll
+  if(IsHorizontal && status->MoveTableMaxX > MTCanvasWidth){
+      // First normalize:
+      XorY-=MTCanvasWidth; // Do not scroll on first page
+      XorY=std::max(0.0,XorY); // Ensure focus is greater than 0
+      XorY=std::min(XorY,(status->MoveTableMaxX-MTCanvasWidth)); // Ensure focus is than scroll max
+      // Then compute percent and apply scroll
+      double percent = XorY / (status->MoveTableMaxX-MTCanvasWidth);
+      status->ScrollX =
+          -(status->MoveTableMaxX - MTCanvasWidth) * percent;
+      // Do not forget to update scrollbar:
+      double maxScroll = bg.width - bar.width;
+      bar.x = maxScroll * percent;
+      bar.x = std::max(bg.x, bar.x);
+      bar.x = std::min(bg.x + maxScroll, bar.x);
+  }
+  else if(status->MoveTableMaxY > MTCanvasHeight){
+      // First normalize:
+      XorY-=MTCanvasHeight; // Do not scroll on first page
+      XorY=std::max(0.0,XorY); // Ensure focus is greater than 0
+      XorY=std::min(XorY,(status->MoveTableMaxY-MTCanvasHeight)); // Ensure focus is than scroll max
+      // Then compute percent and apply scroll
+      double percent = XorY / (status->MoveTableMaxY-MTCanvasHeight);
+      status->ScrollY =
+          -(status->MoveTableMaxY - MTCanvasHeight) * percent;
+      // Do not forget to update scrollbar:
+      double maxScroll = bg.height - bar.height;
+      bar.y = maxScroll * percent;
+      bar.y = std::max(bg.y, bar.y);
+      bar.y = std::min(bg.y + maxScroll, bar.y);
+  }
+}
+
 } // namespace cgeditor
\ No newline at end of file