Implemented clientCoordToRowColumn().

wintable/new/coord.h

@@ -1,19 +1,55 @@
 // 4 december 2014
 
-typedef struct rowcol rowcol;
-
 struct rowcol {
 	intptr_t row;
 	intptr_t column;
 };
 
-static rowcol clientCoordToRowColumn(struct table *t, POINT pt)
+static struct rowcol clientCoordToRowColumn(struct table *t, POINT pt)
 {
-	// TODO
+	RECT r;
+	struct rowcol rc;
+	intptr_t i;
+	RECT colrect;
+
+	// initial values for the PtInRect() check
+	rc.row = -1;
+	rc.column = -1;
+
+	if (GetClientRect(t->hwnd, &r) == 0)
+		panic("error getting Table client rect in clientCoordToRowColumn()");
+	r.top += t->headerHeight;
+	if (PtInRect(&r, p) == 0)
+		return rc;
+
+	// the row is easy
+	rc.row = (pt.y / rowht(t)) + t->yscrollpos;
+
+	// the column... not so much
+	// we scroll p.x, then subtract column widths until we cross the left edge of the control
+	p.x += t->hscrollpos;
+	rc.column = 0;
+	for (i = 0; i < t->nColumns; i++) {
+		// TODO error check
+		SendMessage(t->header, HDM_GETITEMRECT, (WPARAM) i, (LPARAM) (&colrect));
+		p.x -= colrect.right - colrect.left;
+		// use <, not <=, here:
+		// assume r.left and t->hscrollpos == 0;
+		// given the first column is 100 wide,
+		// p.x == 0 (first pixel of col 0) -> p.x - 100 == -100 < 0 -> break
+		// p.x == 99 (last pixel of col 0) -> p.x - 100 == -1 < 0 -> break
+		// p.x == 100 (first pixel of col 1) -> p.x - 100 == 0 >= 0 -> next column
+		if (p.x < r.left)
+			break;
+		rc.column++;
+	}
+	// TODO what happens if the break was never taken?
+
+	return rc;
 }
 
 // same as client coordinates, but stored in a lParam (like the various mouse messages provide)
-static rowcol lParamToRowColumn(struct table *t, LPARAM lParam)
+static struct rowcol lParamToRowColumn(struct table *t, LPARAM lParam)
 {
 	POINT pt;
 
@@ -23,7 +59,7 @@ static rowcol lParamToRowColumn(struct table *t, LPARAM lParam)
 }
 
 // returns TRUE if the row is visible and thus has client coordinates; FALSE otherwise
-static BOOL rowColumnToClientCoord(struct table *t, rowcol rc, struct POINT *pt)
+static BOOL rowColumnToClientCoord(struct table *t, struct rowcol rc, struct POINT *pt)
 {
 	// TODO
 }