Refine IViewportRange API to use 'cursor positions' for x value

Fixes #2484

src/browser/Linkifier.ts

@@ -308,7 +308,7 @@ export class Linkifier implements ILinkifier {
         if (matcher.hoverTooltipCallback) {
           // Note that IViewportRange use 1-based coordinates to align with escape sequences such
           // as CUP which use 1,1 as the default for row/col
-          matcher.hoverTooltipCallback(e, uri, { start: { row: y1 + 1, col: x1 + 1 }, end: { row: y2 + 1, col: x2 } });
+          matcher.hoverTooltipCallback(e, uri, { start: { x: x1, y: y1 }, end: { x: x2, y: y2 } });
         }
       },
       () => {

src/browser/Types.d.ts

@@ -44,13 +44,13 @@ export interface IViewport extends IDisposable {
 }
 
 export interface IViewportRange {
-  start: IViewportCellPosition;
-  end: IViewportCellPosition;
+  start: IViewportRangePosition;
+  end: IViewportRangePosition;
 }
 
-export interface IViewportCellPosition {
-  col: number;
-  row: number;
+export interface IViewportRangePosition {
+  x: number;
+  y: number;
 }
 
 export type LinkMatcherHandler = (event: MouseEvent, uri: string) => void;

typings/xterm.d.ts

@@ -862,29 +862,34 @@ declare module 'xterm' {
    */
   export interface IViewportRange {
     /**
-     * The start cell of the range.
+     * The start of the range.
      */
-    start: IViewportCellPosition;
+    start: IViewportRangePosition;
 
     /**
-     * The end cell of the range.
+     * The end of the range.
      */
-    end: IViewportCellPosition;
+    end: IViewportRangePosition;
   }
 
   /**
    * An object representing a cell position within the viewport of the terminal.
    */
-  interface IViewportCellPosition {
+  interface IViewportRangePosition {
     /**
-     * The column of the cell. Note that this is 1-based; the first column is column 1.
+     * The x position of the cell. This is a 0-based index that refers to the
+     * space in between columns, not the column itself. Index 0 refers to the
+     * left side of the viewport, index `Terminal.cols` refers to the right side
+     * of the viewport. This can be thought of as how a cursor is positioned in
+     * a text editor.
      */
-    col: number;
+    x: number;
 
     /**
-     * The row of the cell. Note that this is 1-based; the first row is row 1.
+     * The y position of the cell. This is a 0-based index that refers to a
+     * specific row.
      */
-    row: number;
+    y: number;
   }
 
   /**