modified PopupLayout

2026-08-09 20:24:21 +05:00
parent 1fc9765a3d
commit 163b86d239
6 changed files with 193 additions and 69 deletions
@@ -0,0 +1,95 @@
+using CursorLang.Interop;
+using CursorLang.Models;
+
+namespace CursorLang.Services;
+
+/// <summary>
+/// Computes the screen point to show the popup at.
+/// </summary>
+/// <remarks>
+/// There is nothing but arithmetic here: where the cursor is, where the caret is and
+/// what the monitor bounds are is figured out by the window itself — it has a handle
+/// of its own for that. The computation is kept apart because it is exactly the place
+/// where a sign or half a size is easy to get wrong, and this way it can be checked
+/// without a single window on screen.
+///
+/// All the values are in physical pixels: monitors have different scaling, and
+/// converting to WPF units halfway would mean rounding twice.
+/// </remarks>
+internal static class PopupLayout
+{
+    /// <summary>
+    /// The popup position next to the anchor point — the cursor or the caret.
+    /// The cursor arrives here as a rectangle of zero size.
+    /// </summary>
+    internal static PopupWindowNative.Point NearAnchor(
+        PopupWindowNative.Rect anchor,
+        AnchorSide side,
+        int offset,
+        int width,
+        int height)
+    {
+        int toLeftOf = anchor.Left - offset - width;
+        int toRightOf = anchor.Right + offset;
+        int above = anchor.Top - offset - height;
+        int below = anchor.Bottom + offset;
+
+        // For the "left" and "right" sides the popup lines up with the anchor point
+        int middle = anchor.Top + (((anchor.Bottom - anchor.Top) - height) / 2);
+
+        (int x, int y) = side switch
+        {
+            AnchorSide.TopLeft => (toLeftOf, above),
+            AnchorSide.TopRight => (toRightOf, above),
+            AnchorSide.Left => (toLeftOf, middle),
+            AnchorSide.Right => (toRightOf, middle),
+            AnchorSide.BottomLeft => (toLeftOf, below),
+            _ => (toRightOf, below),
+        };
+
+        return new PopupWindowNative.Point { X = x, Y = y };
+    }
+
+    /// <summary>
+    /// The popup position in the given corner of the monitor work area.
+    /// </summary>
+    internal static PopupWindowNative.Point OnScreen(
+        PopupWindowNative.Rect work,
+        ScreenPosition position,
+        int margin,
+        int width,
+        int height)
+    {
+        int left = work.Left + margin;
+        int right = work.Right - margin - width;
+        int top = work.Top + margin;
+        int bottom = work.Bottom - margin - height;
+        int centerX = work.Left + ((work.Right - work.Left - width) / 2);
+        int centerY = work.Top + ((work.Bottom - work.Top - height) / 2);
+
+        (int x, int y) = position switch
+        {
+            ScreenPosition.TopLeft => (left, top),
+            ScreenPosition.Top => (centerX, top),
+            ScreenPosition.TopRight => (right, top),
+            ScreenPosition.BottomLeft => (left, bottom),
+            ScreenPosition.Bottom => (centerX, bottom),
+            ScreenPosition.BottomRight => (right, bottom),
+            _ => (centerX, centerY),
+        };
+
+        return new PopupWindowNative.Point { X = x, Y = y };
+    }
+
+    /// <summary>A rectangle of zero size at a point — the mouse cursor as an anchor.</summary>
+    internal static PopupWindowNative.Rect AsAnchor(PopupWindowNative.Point point) => new()
+    {
+        Left = point.X,
+        Top = point.Y,
+        Right = point.X,
+        Bottom = point.Y,
+    };
+
+    /// <summary>WPF units into physical pixels of a monitor with the given scale.</summary>
+    internal static int ToPixels(double wpfUnits, double scale) => (int)Math.Round(wpfUnits * scale);
+}