jetbrains.jetpad.projectional.domUtil.DomUtil.java Source code

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Here is the source code for jetbrains.jetpad.projectional.domUtil.DomUtil.java

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/*
 * Copyright 2012-2016 JetBrains s.r.o
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package jetbrains.jetpad.projectional.domUtil;

import com.google.gwt.dom.client.Element;
import com.google.gwt.user.client.Window;
import jetbrains.jetpad.geometry.Rectangle;
import jetbrains.jetpad.geometry.Vector;

import static com.google.gwt.query.client.GQuery.$;

public class DomUtil {
    public static boolean hasScrollers(Element ctx) {
        if (ctx.getParentElement() == null)
            return false;
        if (hasScroller(ctx))
            return true;
        return hasScrollers(ctx.getParentElement());
    }

    private static boolean hasScroller(Element e) {
        String overflow = $(e).css("overflow");
        return "scroll".equals(overflow) || "auto".equals(overflow);
    }

    public static Rectangle visiblePart(Element ctx) {
        return DomUtil.visiblePart(ctx, new Rectangle(0, 0, ctx.getScrollWidth(), ctx.getScrollHeight()));
    }

    public static Rectangle visiblePart(Element ctx, Rectangle rect) {
        while (true) {
            if (ctx.getOffsetParent() == null) {
                Rectangle visibleArea = new Rectangle(Window.getScrollLeft(), Window.getScrollTop(),
                        Window.getClientWidth(), Window.getClientHeight());
                return visibleArea.intersect(rect);
            } else {
                Rectangle visible;
                if (hasScroller(ctx)) {
                    visible = new Rectangle(0, 0, ctx.getClientWidth(), ctx.getClientHeight());
                    Vector scroll = new Vector(ctx.getScrollLeft(), ctx.getScrollTop());
                    rect = rect.sub(scroll);
                } else {
                    visible = new Rectangle(0, 0, ctx.getScrollWidth(), ctx.getScrollHeight());
                }

                Rectangle newRect = visible.intersect(rect);
                Vector offset = new Vector(ctx.getOffsetLeft(), ctx.getOffsetTop());

                ctx = ctx.getOffsetParent();
                rect = newRect.add(offset);
            }
        }
    }
}