Returning coords with Clickable event. Usinsg them to position cursor when clicking in a textfield

src/counter.cg

@@ -8,7 +8,7 @@ view = count \
         children = [
             Text({ content = str(count), x = 0, y = 20 }),
             Clickable {
-                event = "increment",
+                event = Increment,
                 child = Rect { w = 100, h = 40, color = "blue" }
             }
         ]

src/runtime.ts

@@ -74,9 +74,26 @@ export function runApp(app: App, canvas: HTMLCanvasElement) {
         }
 
 
-        const event = hitTest(x, y);
-        if (event) {
-            handleEvent(event);
+        const hitResult = hitTest(x, y);
+        if (hitResult) {
+            const { event, relativeX, relativeY } = hitResult;
+
+            if (event.kind === 'constructor') {
+                const eventWithCoords: Value = {
+                    kind: 'constructor',
+                    name: event.name,
+                    args: [{
+                        kind: 'record',
+                        fields: {
+                            x: { kind: 'int', value: Math.floor(relativeX) },
+                            y: { kind: 'int', value: Math.floor(relativeY) },
+                        }
+                    }]
+                };
+                handleEvent(eventWithCoords);
+            } else {
+                handleEvent(event);
+            }
         }
     });
 

src/textinput-test.cg

@@ -1,21 +1,31 @@
 routeKeyToFocused = state event \
   (state.focusedInput == "email"
   | True \
-    newInputState = textInput2.update state.email event;
+    newInputState = textInput.update state.email event;
     state.{ email = newInputState }
   | False \
-    newInputState = textInput2.update state.password event;
+    newInputState = textInput.update state.password event;
     state.{ password = newInputState });
 
 init = {
   focusedInput = "email",
-  email = textInput2.init "",
-  password = textInput2.init ""
+  email = textInput.init "",
+  password = textInput.init ""
 };
 
 update = state event \ event
-  | FocusEmail \ state.{ focusedInput = "email" }
-  | FocusPassword \ state.{ focusedInput = "password" }
+  | FocusEmail coords \ (
+    newState = state.{ focusedInput = "email" };
+    newInputState = textInput.update state.email (Clicked coords);
+    newState.{ email = newInputState }
+    )
+
+  | FocusPassword coords \ (
+    newState = state.{ focusedInput = "password" };
+    newInputState = textInput.update state.password (Clicked coords);
+    newState.{ password = newInputState }
+    )
+
   | ArrowLeft \ routeKeyToFocused state ArrowLeft
   | ArrowRight \ routeKeyToFocused state ArrowRight
   | Backspace \ routeKeyToFocused state Backspace
@@ -29,13 +39,13 @@ view = state viewport \
    child = Column {
      gap = 10,
      children = [
-       textInput2.view state.email {
+       textInput.view state.email {
          focused = state.focusedInput == "email",
          onFocus = FocusEmail,
          w = 300,
          h = 40
        },
-       textInput2.view state.password {
+       textInput.view state.password {
          focused = state.focusedInput == "password",
          onFocus = FocusPassword,
          w = 300,

src/ui-components.cg

@@ -33,7 +33,23 @@ calcScrollOffset = text cursorPos scrollOffset inputWidth \
     | True \ cursorX - inputWidth + 20
     | False \ scrollOffset));
 
-textInput2 = {
+findPosHelper = text targetX index \
+  (index >= len text)
+  | True \ len text
+  | False \ (
+    widthSoFar = measureText (slice text 0 index);
+    widthNext = measureText (slice text 0 (index + 1));
+    midpoint = (widthSoFar + widthNext) / 2;
+    (targetX < midpoint
+    | True \ index
+    | False \ findPosHelper text targetX (index + 1))
+  );
+
+findCursorPos = text clickX scrollOffset inputPadding \
+  adjustedX = clickX + scrollOffset - inputPadding;
+  findPosHelper text adjustedX 0;
+
+textInput = {
   # init : String \ State
   init = text \ { text = text, cursorPos = 0, scrollOffset = 0 },
 
@@ -65,6 +81,12 @@ textInput2 = {
     { text = newText, cursorPos = newCursorPos, scrollOffset = newScroll }
     )
 
+    | Clicked coords \ (
+        newCursorPos = findCursorPos state.text coords.x state.scrollOffset 8;
+        newScroll = calcScrollOffset state.text newCursorPos state.scrollOffset 284;
+        { text = state.text, cursorPos = newCursorPos, scrollOffset = newScroll }
+        )
+
     | _ \ state,
 
   view = state config \

src/ui.ts

@@ -228,11 +228,15 @@ function measure(ui: UIValue): { width: number, height: number } {
     }
 }
 
-export function hitTest(x: number, y: number): Value | null {
+export function hitTest(x: number, y: number): { event: Value, relativeX: number, relativeY: number } | null {
     for (const region of clickRegions) {
         if (x >= region.x && x < region.x + region.width &&
            y >= region.y && y < region.y + region.height) {
-            return region.event;
+            return {
+                event: region.event,
+                relativeX: x - region.x,
+                relativeY: y - region.y,
+            };
         }
     }
     return null;