Java DivElement.getOffsetWidth方法代码示例

import com.google.gwt.dom.client.DivElement; //导入方法依赖的package包/类
private void updateFontDimensions() {

		// Test element for font size
		DivElement test = Document.get().createDivElement();
		test.setAttribute("style", "position: absolute;");
		test.setInnerHTML("X");
		term.appendChild(test);

		fontW = test.getClientWidth();
		fontH = test.getClientHeight();
		if (fontW <= 0 || fontW > 100) {
			fontW = test.getOffsetWidth();
		}
		if (fontH <= 0 || fontH > 100) {
			fontH = test.getOffsetHeight();
		}
		if (fontW <= 0 || fontW > 100) {
			fontW = 1;
		}
		if (fontH <= 0 || fontH > 100) {
			fontH = 1;
		}
		term.removeChild(test);
	}
 

import com.google.gwt.dom.client.DivElement; //导入方法依赖的package包/类
private static int getVerticalScrollbarWidth() {
  // We only calculate the vertical scroll bar width once, then we store it in the static field
  // verticalScrollbarWidth. If the field is non-zero, we don't need to calculate it again.
  if (verticalScrollbarWidth == 0) {
    // The following code will calculate (on the fly) the width of a vertical scroll bar.
    // We'll create two divs, one inside the other and add the outer div to the document body,
    // but off-screen where the user won't see it.
    // We'll measure the width of the inner div twice: (first) when the outer div's vertical
    // scrollbar is hidden and (second) when the outer div's vertical scrollbar is visible.
    // The width of inner div will be smaller when outer div's vertical scrollbar is visible.
    // By subtracting the two measurements, we can calculate the width of the vertical scrollbar.

    // I used code from the following websites as reference material:
    // http://jdsharp.us/jQuery/minute/calculate-scrollbar-width.php
    // http://www.fleegix.org/articles/2006-05-30-getting-the-scrollbar-width-in-pixels

    Document document = Document.get();

    // Create an outer div.
    DivElement outerDiv = document.createDivElement();
    Style outerDivStyle = outerDiv.getStyle();
    // Use absolute positioning and set the top/left so that it is off-screen.
    // We don't want the user to see anything while we do this calculation.
    outerDivStyle.setProperty("position", "absolute");
    outerDivStyle.setProperty("top", "-1000px");
    outerDivStyle.setProperty("left", "-1000px");
    // Set the width and height of the outer div to a fixed size in pixels.
    outerDivStyle.setProperty("width", "100px");
    outerDivStyle.setProperty("height", "50px");
    // Hide the outer div's scrollbar by setting the "overflow" property to "hidden".
    outerDivStyle.setProperty("overflow", "hidden");

    // Create an inner div and put it inside the outer div.
    DivElement innerDiv = document.createDivElement();
    Style innerDivStyle = innerDiv.getStyle();
    // Set the height of the inner div to be 4 times the height of the outer div so that a
    // vertical scrollbar will be necessary (but hidden for now) on the outer div.
    innerDivStyle.setProperty("height", "200px");
    outerDiv.appendChild(innerDiv);

    // Temporarily add the outer div to the document body. It's off-screen so the user won't
    // actually see anything.
    Element bodyElement = document.getElementsByTagName("body").getItem(0);
    bodyElement.appendChild(outerDiv);

    // Get the width of the inner div while the outer div's vertical scrollbar is hidden.
    int widthWithoutScrollbar = innerDiv.getOffsetWidth();
    // Show the outer div's vertical scrollbar by setting the "overflow" property to "auto".
    outerDivStyle.setProperty("overflow", "auto");
    // Now, get the width of the inner div while the vertical scrollbar is visible.
    int widthWithScrollbar = innerDiv.getOffsetWidth();

    // Remove the outer div from the document body.
    bodyElement.removeChild(outerDiv);

    // Calculate the width of the vertical scrollbar by subtracting the two widths.
    verticalScrollbarWidth = widthWithoutScrollbar - widthWithScrollbar;
  }

  return verticalScrollbarWidth;
}