text: /*
   * Copyright (C) 2013 Google Inc. All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are
   * met:
   *
   *     * Redistributions of source code must retain the above copyright
   * notice, this list of conditions and the following disclaimer.
   *     * Redistributions in binary form must reproduce the above
   * copyright notice, this list of conditions and the following disclaimer
   * in the documentation and/or other materials provided with the
   * distribution.
   *     * Neither the name of Google Inc. nor the names of its
   * contributors may be used to endorse or promote products derived from
   * this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
   * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  /**
   * @unrestricted
   */
  PerfUI.OverviewGrid = class {
    /**
     * @param {string} prefix
     */
    constructor(prefix) {
      this.element = createElement('div');
      this.element.id = prefix + '-overview-container';
  
      this._grid = new PerfUI.TimelineGrid();
      this._grid.element.id = prefix + '-overview-grid';
      this._grid.setScrollTop(0);
  
      this.element.appendChild(this._grid.element);
  
      this._window = new PerfUI.OverviewGrid.Window(this.element, this._grid.dividersLabelBarElement);
    }
  
    /**
     * @return {number}
     */
    clientWidth() {
      return this.element.clientWidth;
    }
  
    /**
     * @param {!PerfUI.TimelineGrid.Calculator} calculator
     */
    updateDividers(calculator) {
      this._grid.updateDividers(calculator);
    }
  
    /**
     * @param {!Array.<!Element>} dividers
     */
    addEventDividers(dividers) {
      this._grid.addEventDividers(dividers);
    }
  
    removeEventDividers() {
      this._grid.removeEventDividers();
    }
  
    reset() {
      this._window.reset();
    }
  
    /**
     * @return {number}
     */
    windowLeft() {
      return this._window.windowLeft;
    }
  
    /**
     * @return {number}
     */
    windowRight() {
      return this._window.windowRight;
    }
  
    /**
     * @param {number} left
     * @param {number} right
     */
    setWindow(left, right) {
      this._window._setWindow(left, right);
    }
  
    /**
     * @param {symbol} eventType
     * @param {function(!Common.Event)} listener
     * @param {!Object=} thisObject
     * @return {!Common.EventTarget.EventDescriptor}
     */
    addEventListener(eventType, listener, thisObject) {
      return this._window.addEventListener(eventType, listener, thisObject);
    }
  
    /**
     * @param {?function(!Event):boolean} clickHandler
     */
    setClickHandler(clickHandler) {
      this._window.setClickHandler(clickHandler);
    }
  
    /**
     * @param {number} zoomFactor
     * @param {number} referencePoint
     */
    zoom(zoomFactor, referencePoint) {
      this._window._zoom(zoomFactor, referencePoint);
    }
  
    /**
     * @param {boolean} enabled
     */
    setResizeEnabled(enabled) {
      this._window.setEnabled(enabled);
    }
  };
  
  PerfUI.OverviewGrid.MinSelectableSize = 14;
  
  PerfUI.OverviewGrid.WindowScrollSpeedFactor = .3;
  
  PerfUI.OverviewGrid.ResizerOffset = 3.5;  // half pixel because offset values are not rounded but ceiled
  
  /**
   * @unrestricted
   */
  PerfUI.OverviewGrid.Window = class extends Common.Object {
    /**
     * @param {!Element} parentElement
     * @param {!Element=} dividersLabelBarElement
     */
    constructor(parentElement, dividersLabelBarElement) {
      super();
      this._parentElement = parentElement;
  
      UI.installDragHandle(
          this._parentElement, this._startWindowSelectorDragging.bind(this), this._windowSelectorDragging.bind(this),
          this._endWindowSelectorDragging.bind(this), 'text', null);
      if (dividersLabelBarElement) {
        UI.installDragHandle(
            dividersLabelBarElement, this._startWindowDragging.bind(this), this._windowDragging.bind(this), null,
            '-webkit-grabbing', '-webkit-grab');
      }
  
      this._parentElement.addEventListener('mousewheel', this._onMouseWheel.bind(this), true);
      this._parentElement.addEventListener('dblclick', this._resizeWindowMaximum.bind(this), true);
      UI.appendStyle(this._parentElement, 'perf_ui/overviewGrid.css');
  
      this._leftResizeElement = parentElement.createChild('div', 'overview-grid-window-resizer');
      UI.installDragHandle(
          this._leftResizeElement, this._resizerElementStartDragging.bind(this),
          this._leftResizeElementDragging.bind(this), null, 'ew-resize');
      this._rightResizeElement = parentElement.createChild('div', 'overview-grid-window-resizer');
      UI.installDragHandle(
          this._rightResizeElement, this._resizerElementStartDragging.bind(this),
          this._rightResizeElementDragging.bind(this), null, 'ew-resize');
  
      this._leftCurtainElement = parentElement.createChild('div', 'window-curtain-left');
      this._rightCurtainElement = parentElement.createChild('div', 'window-curtain-right');
      this.reset();
    }
  
    reset() {
      this.windowLeft = 0.0;
      this.windowRight = 1.0;
      this.setEnabled(true);
      this._updateCurtains();
    }
  
    /**
     * @param {boolean} enabled
     */
    setEnabled(enabled) {
      this._enabled = enabled;
    }
  
    /**
     * @param {?function(!Event):boolean} clickHandler
     */
    setClickHandler(clickHandler) {
      this._clickHandler = clickHandler;
    }
  
    /**
     * @param {!Event} event
     */
    _resizerElementStartDragging(event) {
      if (!this._enabled)
        return false;
      this._resizerParentOffsetLeft = event.pageX - event.offsetX - event.target.offsetLeft;
      event.stopPropagation();
      return true;
    }
  
    /**
     * @param {!Event} event
     */
    _leftResizeElementDragging(event) {
      this._resizeWindowLeft(event.pageX - this._resizerParentOffsetLeft);
      event.preventDefault();
    }
  
    /**
     * @param {!Event} event
     */
    _rightResizeElementDragging(event) {
      this._resizeWindowRight(event.pageX - this._resizerParentOffsetLeft);
      event.preventDefault();
    }
  
    /**
     * @param {!Event} event
     * @return {boolean}
     */
    _startWindowSelectorDragging(event) {
      if (!this._enabled)
        return false;
      this._offsetLeft = this._parentElement.totalOffsetLeft();
      var position = event.x - this._offsetLeft;
      this._overviewWindowSelector = new PerfUI.OverviewGrid.WindowSelector(this._parentElement, position);
      return true;
    }
  
    /**
     * @param {!Event} event
     */
    _windowSelectorDragging(event) {
      this._overviewWindowSelector._updatePosition(event.x - this._offsetLeft);
      event.preventDefault();
    }
  
    /**
     * @param {!Event} event
     */
    _endWindowSelectorDragging(event) {
      var window = this._overviewWindowSelector._close(event.x - this._offsetLeft);
      delete this._overviewWindowSelector;
      var clickThreshold = 3;
      if (window.end - window.start < clickThreshold) {
        if (this._clickHandler && this._clickHandler.call(null, event))
          return;
        var middle = window.end;
        window.start = Math.max(0, middle - PerfUI.OverviewGrid.MinSelectableSize / 2);
        window.end = Math.min(this._parentElement.clientWidth, middle + PerfUI.OverviewGrid.MinSelectableSize / 2);
      } else if (window.end - window.start < PerfUI.OverviewGrid.MinSelectableSize) {
        if (this._parentElement.clientWidth - window.end > PerfUI.OverviewGrid.MinSelectableSize)
          window.end = window.start + PerfUI.OverviewGrid.MinSelectableSize;
        else
          window.start = window.end - PerfUI.OverviewGrid.MinSelectableSize;
      }
      this._setWindowPosition(window.start, window.end);
    }
  
    /**
     * @param {!Event} event
     * @return {boolean}
     */
    _startWindowDragging(event) {
      this._dragStartPoint = event.pageX;
      this._dragStartLeft = this.windowLeft;
      this._dragStartRight = this.windowRight;
      event.stopPropagation();
      return true;
    }
  
    /**
     * @param {!Event} event
     */
    _windowDragging(event) {
      event.preventDefault();
      var delta = (event.pageX - this._dragStartPoint) / this._parentElement.clientWidth;
      if (this._dragStartLeft + delta < 0)
        delta = -this._dragStartLeft;
  
      if (this._dragStartRight + delta > 1)
        delta = 1 - this._dragStartRight;
  
      this._setWindow(this._dragStartLeft + delta, this._dragStartRight + delta);
    }
  
    /**
     * @param {number} start
     */
    _resizeWindowLeft(start) {
      // Glue to edge.
      if (start < 10)
        start = 0;
      else if (start > this._rightResizeElement.offsetLeft - 4)
        start = this._rightResizeElement.offsetLeft - 4;
      this._setWindowPosition(start, null);
    }
  
    /**
     * @param {number} end
     */
    _resizeWindowRight(end) {
      // Glue to edge.
      if (end > this._parentElement.clientWidth - 10)
        end = this._parentElement.clientWidth;
      else if (end < this._leftResizeElement.offsetLeft + PerfUI.OverviewGrid.MinSelectableSize)
        end = this._leftResizeElement.offsetLeft + PerfUI.OverviewGrid.MinSelectableSize;
      this._setWindowPosition(null, end);
    }
  
    _resizeWindowMaximum() {
      this._setWindowPosition(0, this._parentElement.clientWidth);
    }
  
    /**
     * @param {number} windowLeft
     * @param {number} windowRight
     */
    _setWindow(windowLeft, windowRight) {
      this.windowLeft = windowLeft;
      this.windowRight = windowRight;
      this._updateCurtains();
      this.dispatchEventToListeners(PerfUI.OverviewGrid.Events.WindowChanged);
    }
  
    _updateCurtains() {
      var left = this.windowLeft;
      var right = this.windowRight;
      var width = right - left;
  
      // We allow actual time window to be arbitrarily small but don't want the UI window to be too small.
      var widthInPixels = width * this._parentElement.clientWidth;
      var minWidthInPixels = PerfUI.OverviewGrid.MinSelectableSize / 2;
      if (widthInPixels < minWidthInPixels) {
        var factor = minWidthInPixels / widthInPixels;
        left = ((this.windowRight + this.windowLeft) - width * factor) / 2;
        right = ((this.windowRight + this.windowLeft) + width * factor) / 2;
      }
      this._leftResizeElement.style.left = (100 * left).toFixed(2) + '%';
      this._rightResizeElement.style.left = (100 * right).toFixed(2) + '%';
  
      this._leftCurtainElement.style.width = (100 * left).toFixed(2) + '%';
      this._rightCurtainElement.style.width = (100 * (1 - right)).toFixed(2) + '%';
    }
  
    /**
     * @param {?number} start
     * @param {?number} end
     */
    _setWindowPosition(start, end) {
      var clientWidth = this._parentElement.clientWidth;
      var windowLeft = typeof start === 'number' ? start / clientWidth : this.windowLeft;
      var windowRight = typeof end === 'number' ? end / clientWidth : this.windowRight;
      this._setWindow(windowLeft, windowRight);
    }
  
    /**
     * @param {!Event} event
     */
    _onMouseWheel(event) {
      if (!this._enabled)
        return;
      if (typeof event.wheelDeltaY === 'number' && event.wheelDeltaY) {
        const zoomFactor = 1.1;
        const mouseWheelZoomSpeed = 1 / 120;
  
        var reference = event.offsetX / event.target.clientWidth;
        this._zoom(Math.pow(zoomFactor, -event.wheelDeltaY * mouseWheelZoomSpeed), reference);
      }
      if (typeof event.wheelDeltaX === 'number' && event.wheelDeltaX) {
        var offset = Math.round(event.wheelDeltaX * PerfUI.OverviewGrid.WindowScrollSpeedFactor);
        var windowLeft = this._leftResizeElement.offsetLeft + PerfUI.OverviewGrid.ResizerOffset;
        var windowRight = this._rightResizeElement.offsetLeft + PerfUI.OverviewGrid.ResizerOffset;
  
        if (windowLeft - offset < 0)
          offset = windowLeft;
  
        if (windowRight - offset > this._parentElement.clientWidth)
          offset = windowRight - this._parentElement.clientWidth;
  
        this._setWindowPosition(windowLeft - offset, windowRight - offset);
  
        event.preventDefault();
      }
    }
  
    /**
     * @param {number} factor
     * @param {number} reference
     */
    _zoom(factor, reference) {
      var left = this.windowLeft;
      var right = this.windowRight;
      var windowSize = right - left;
      var newWindowSize = factor * windowSize;
      if (newWindowSize > 1) {
        newWindowSize = 1;
        factor = newWindowSize / windowSize;
      }
      left = reference + (left - reference) * factor;
      left = Number.constrain(left, 0, 1 - newWindowSize);
  
      right = reference + (right - reference) * factor;
      right = Number.constrain(right, newWindowSize, 1);
      this._setWindow(left, right);
    }
  };
  
  /** @enum {symbol} */
  PerfUI.OverviewGrid.Events = {
    WindowChanged: Symbol('WindowChanged')
  };
  
  /**
   * @unrestricted
   */
  PerfUI.OverviewGrid.WindowSelector = class {
    constructor(parent, position) {
      this._startPosition = position;
      this._width = parent.offsetWidth;
      this._windowSelector = createElement('div');
      this._windowSelector.className = 'overview-grid-window-selector';
      this._windowSelector.style.left = this._startPosition + 'px';
      this._windowSelector.style.right = this._width - this._startPosition + 'px';
      parent.appendChild(this._windowSelector);
    }
  
    _close(position) {
      position = Math.max(0, Math.min(position, this._width));
      this._windowSelector.remove();
      return this._startPosition < position ? {start: this._startPosition, end: position} :
                                              {start: position, end: this._startPosition};
    }
  
    _updatePosition(position) {
      position = Math.max(0, Math.min(position, this._width));
      if (position < this._startPosition) {
        this._windowSelector.style.left = position + 'px';
        this._windowSelector.style.right = this._width - this._startPosition + 'px';
      } else {
        this._windowSelector.style.left = this._startPosition + 'px';
        this._windowSelector.style.right = this._width - position + 'px';
      }
    }
  };
  