private _onMouseMove()

in src/SelectionManager.ts [548:606]
37 lines of code
15 McCabe index (conditional complexity)

  private _onMouseMove(event: MouseEvent): void {
    // If the mousemove listener is active it means that a selection is
    // currently being made, we should stop propogation to prevent mouse events
    // to be sent to the pty.
    event.stopImmediatePropagation();

    // Record the previous position so we know whether to redraw the selection
    // at the end.
    const previousSelectionEnd = this._model.selectionEnd ? [this._model.selectionEnd[0], this._model.selectionEnd[1]] : null;

    // Set the initial selection end based on the mouse coordinates
    this._model.selectionEnd = this._getMouseBufferCoords(event);
    if (!this._model.selectionEnd) {
      this.refresh(true);
      return;
    }

    // Select the entire line if line select mode is active.
    if (this._activeSelectionMode === SelectionMode.LINE) {
      if (this._model.selectionEnd[1] < this._model.selectionStart[1]) {
        this._model.selectionEnd[0] = 0;
      } else {
        this._model.selectionEnd[0] = this._terminal.cols;
      }
    } else if (this._activeSelectionMode === SelectionMode.WORD) {
      this._selectToWordAt(this._model.selectionEnd);
    }

    // Determine the amount of scrolling that will happen.
    this._dragScrollAmount = this._getMouseEventScrollAmount(event);

    // If the cursor was above or below the viewport, make sure it's at the
    // start or end of the viewport respectively. This should only happen when
    // NOT in column select mode.
    if (this._activeSelectionMode !== SelectionMode.COLUMN) {
      if (this._dragScrollAmount > 0) {
        this._model.selectionEnd[0] = this._terminal.cols;
      } else if (this._dragScrollAmount < 0) {
        this._model.selectionEnd[0] = 0;
      }
    }

    // If the character is a wide character include the cell to the right in the
    // selection. Note that selections at the very end of the line will never
    // have a character.
    if (this._model.selectionEnd[1] < this._buffer.lines.length) {
      const char = this._buffer.lines.get(this._model.selectionEnd[1]).get(this._model.selectionEnd[0]);
      if (char && char[CHAR_DATA_WIDTH_INDEX] === 0) {
        this._model.selectionEnd[0]++;
      }
    }

    // Only draw here if the selection changes.
    if (!previousSelectionEnd ||
      previousSelectionEnd[0] !== this._model.selectionEnd[0] ||
      previousSelectionEnd[1] !== this._model.selectionEnd[1]) {
      this.refresh(true);
    }
  }