More work on SelectionManager

src/SelectionManager.ts

@@ -12,12 +12,14 @@ export class SelectionManager {
 
   private _buffer: CircularList<any>;
   private _rowContainer: HTMLElement;
+  private _selectionContainer: HTMLElement;
   private _charMeasure: CharMeasure;
 
   private _mouseMoveListener: EventListener;
 
-  constructor(buffer: CircularList<any>, rowContainer: HTMLElement, charMeasure: CharMeasure) {
+  constructor(buffer: CircularList<any>, rowContainer: HTMLElement, selectionContainer: HTMLElement, charMeasure: CharMeasure) {
     this._rowContainer = rowContainer;
+    this._selectionContainer = selectionContainer;
     this._buffer = buffer;
     this._charMeasure = charMeasure;
     this._attachListeners();
@@ -38,10 +40,43 @@ export class SelectionManager {
     return '';
   }
 
+  /**
+   * Redraws the selection.
+   */
+  public refresh(): void {
+    console.log(`Selection: Start: (${this._selectionStart[0]}, ${this._selectionStart[1]}), End: (${this._selectionEnd[0]}, ${this._selectionEnd[1]})`);
+    this._selectionContainer.innerHTML = `<div><br><br></div>`;
+  }
+
+  /**
+   * Handle the buffer being trimmed, adjust the selection position.
+   * @param amount The amount the buffer is being trimmed.
+   */
   private _onTrim(amount: number) {
     // TODO: Somehow map the selection coordinates with the list that is constantly being trimmed
     //       Maybe we need an ID in the CircularList that starts from 0 for the first entry and increments
     console.log('trimmed: ' + amount);
+
+    // Adjust the selection position based on the trimmed amount.
+    this._selectionStart[0] -= amount;
+    this._selectionEnd[0] -= amount;
+
+    // The selection has moved off the buffer, clear it.
+    if (this._selectionEnd[0] < 0) {
+      this._selectionStart = null;
+      this._selectionEnd = null;
+      this.refresh();
+      return;
+    }
+
+    // If the selection start is trimmed, ensure the start column is 0.
+    if (this._selectionStart[0] < 0) {
+      this._selectionStart[1] = 0;
+    }
+
+    // Maybe SelectionManager could maintain it's own ID concept from 0 (top of
+    // buffer) to n (size of buffer). On trim just increment the selection if
+    // necessary. This would reduce complexity and potentially not need the
   }
 
   private _getMouseBufferCoords(event: MouseEvent) {
@@ -58,6 +93,8 @@ export class SelectionManager {
 
   private _onMouseMove(event: MouseEvent) {
     this._selectionEnd = this._getMouseBufferCoords(event);
+    // TODO: Only draw here if the selection changes
+    this.refresh();
   }
 
   private _onMouseUp(event: MouseEvent) {