Fix for 'Aborting layout after 100 passess' (#13359)

'Aborting layout after 100 passes.' is caused by LayoutManager falling
into a loop on rounding fractional layout slot sizes up and down while
trying to fit layout's content in the space available. LayoutManager
round always up, that causes this issue with IE9+ and Chrome. This
change helps LayoutManager to round fractional sizes down for browsers
that causes problems if rounded up.

Browsers may fall into the loop especially with a zoom level other than
100%. Not with any zoom level though. Problematic zoom level varies by
browser. OrderedLayoutExpandTest uses zoom levels other than 100%. Test
for Chrome is the only one that really is able to reproduce error
without the fix. IE9/10 would too, but the zoom level could not be set
exactly to the required 95% for IE. Test works best as a regression test
for other browsers.

Change-Id: Ie840b074df5fed5ea3b15fba9a6fd372a5c0b76a

2 files changed, 241 insertions, 0 deletions

diff --git a/uitest/src/com/vaadin/tests/components/orderedlayout/OrderedLayoutExpand.java b/uitest/src/com/vaadin/tests/components/orderedlayout/OrderedLayoutExpand.java
new file mode 100644
index 0000000000..e51e9a49a5
--- /dev/null
+++ b/uitest/src/com/vaadin/tests/components/orderedlayout/OrderedLayoutExpand.java
@@ -0,0 +1,109 @@
+/*
+ * Copyright 2000-2014 Vaadin Ltd.
+ * 
+ * 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 com.vaadin.tests.components.orderedlayout;
+
+import com.vaadin.server.VaadinRequest;
+import com.vaadin.tests.components.AbstractTestUI;
+import com.vaadin.ui.Alignment;
+import com.vaadin.ui.Component;
+import com.vaadin.ui.HorizontalLayout;
+import com.vaadin.ui.Label;
+import com.vaadin.ui.UI;
+
+@SuppressWarnings("serial")
+public class OrderedLayoutExpand extends AbstractTestUI {
+
+    @Override
+    protected void setup(VaadinRequest request) {
+
+        ThreeColumnLayout layout = new ThreeColumnLayout(
+                createLabelWithUndefinedSize("first component"),
+                createLabelWithUndefinedSize("second component"),
+                createLabelWithUndefinedSize("third component"));
+
+        addComponent(layout);
+        setWidth("600px");
+
+        if (UI.getCurrent().getPage().getWebBrowser().isChrome()) {
+            getPage().getStyles().add("body { zoom: 1.10; }");
+        }
+    }
+
+    @Override
+    protected String getTestDescription() {
+        StringBuilder sb = new StringBuilder(
+                "You should not see 'Aborting layout after 100 passes.' error with debug mode and ");
+        if (UI.getCurrent().getPage().getWebBrowser().isChrome()) {
+            sb.append(" Zoom is ");
+            sb.append("1.10");
+        } else {
+            sb.append(" zoom level 95%.");
+        }
+        return sb.toString();
+    }
+
+    @Override
+    protected Integer getTicketNumber() {
+        return 13359;
+    }
+
+    private Label createLabelWithUndefinedSize(String caption) {
+        Label label = new Label(caption);
+        label.setSizeUndefined();
+        return label;
+    }
+
+    private static class ThreeColumnLayout extends HorizontalLayout {
+        public ThreeColumnLayout(Component leftComponent,
+                Component centerComponent, Component rightComponent) {
+            setWidth("100%");
+            setMargin(true);
+            Component left = createLeftHolder(leftComponent);
+            this.addComponent(left);
+            setComponentAlignment(left, Alignment.MIDDLE_LEFT);
+            setExpandRatio(left, 1f);
+            Component center = createCenterHolder(centerComponent);
+            this.addComponent(center);
+            setComponentAlignment(center, Alignment.MIDDLE_CENTER);
+            setExpandRatio(center, 0f);
+            Component right = createRightHolder(rightComponent);
+            this.addComponent(right);
+            setComponentAlignment(right, Alignment.MIDDLE_RIGHT);
+            setExpandRatio(right, 1f);
+        }
+
+        private Component createLeftHolder(Component c) {
+            HorizontalLayout hl = new HorizontalLayout();
+            hl.addComponent(c);
+            hl.setWidth(100, Unit.PERCENTAGE);
+            return hl;
+        }
+
+        private Component createCenterHolder(Component c) {
+            HorizontalLayout hl = new HorizontalLayout();
+            hl.addComponent(c);
+            hl.setComponentAlignment(c, Alignment.MIDDLE_CENTER);
+            return hl;
+        }
+
+        private Component createRightHolder(Component c) {
+            HorizontalLayout hl = new HorizontalLayout();
+            hl.addComponent(c);
+            hl.setWidth(100, Unit.PERCENTAGE);
+            return hl;
+        }
+    }
+}
diff --git a/uitest/src/com/vaadin/tests/components/orderedlayout/OrderedLayoutExpandTest.java b/uitest/src/com/vaadin/tests/components/orderedlayout/OrderedLayoutExpandTest.java
new file mode 100644
index 0000000000..46b5f6b8b0
--- /dev/null
+++ b/uitest/src/com/vaadin/tests/components/orderedlayout/OrderedLayoutExpandTest.java
@@ -0,0 +1,132 @@
+/*
+ * Copyright 2000-2014 Vaadin Ltd.
+ * 
+ * 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 com.vaadin.tests.components.orderedlayout;
+
+import java.util.List;
+
+import org.junit.Assert;
+import org.junit.Test;
+import org.openqa.selenium.By;
+import org.openqa.selenium.Keys;
+import org.openqa.selenium.NoSuchElementException;
+import org.openqa.selenium.WebElement;
+import org.openqa.selenium.remote.DesiredCapabilities;
+
+import com.vaadin.tests.tb3.MultiBrowserTest;
+
+public class OrderedLayoutExpandTest extends MultiBrowserTest {
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see com.vaadin.tests.tb3.MultiBrowserTest#getBrowsersToTest()
+     */
+    @Override
+    public List<DesiredCapabilities> getBrowsersToTest() {
+        List<DesiredCapabilities> browsersToTest = super.getBrowsersToTest();
+
+        // Not sure why, but IE11 might give the following error message:
+        // "org.openqa.selenium.WebDriverException: Unexpected error launching
+        // Internet Explorer. Browser zoom level was set to 75%. It should be
+        // set to 100%".
+
+        // setting "ignoreZoomSetting" capability to true seems to help, but if
+        // it keeps bugging, just skip the IE11 completely bu uncommenting the
+        // line below.
+        // browsersToTest.remove(Browser.IE11.getDesiredCapabilities());
+        Browser.IE11.getDesiredCapabilities().setCapability(
+                "ignoreZoomSetting", true);
+
+        // Can't test with IE8 with a zoom level other than 100%. IE8 could be
+        // removed to speed up the test run.
+        // browsersToTest.remove(Browser.IE8.getDesiredCapabilities());
+
+        return browsersToTest;
+    }
+
+    @Test
+    public void testNoAbortingLayoutAfter100PassesError() throws Exception {
+        setDebug(true);
+        openTestURL();
+
+        if (!getDesiredCapabilities().equals(
+                Browser.CHROME.getDesiredCapabilities())) {
+            // Chrome uses css to to set zoom level to 110% that is known to
+            // cause issues with the test app.
+            // Other browsers tries to set browser's zoom level directly.
+            WebElement html = driver.findElement(By.tagName("html"));
+            // reset to 100% just in case
+            html.sendKeys(Keys.chord(Keys.CONTROL, "0"));
+            // zoom browser to 75% (ie) or 90% (FF). It depends on browser
+            // how much "Ctrl + '-'" zooms out.
+            html.sendKeys(Keys.chord(Keys.CONTROL, Keys.SUBTRACT));
+        }
+
+        // open debug window's Examine component hierarchy tab
+        openDebugExamineComponentHierarchyTab();
+
+        // click "Check layouts for potential problems" button
+        clickDebugCheckLayoutsForPotentialProblems();
+
+        // find div containing a successful layout analyze result
+        WebElement pass = findLayoutAnalyzePassElement();
+        // find div containing a error message with
+        // "Aborting layout after 100 passess" message.
+        WebElement error = findLayoutAnalyzeAbortedElement();
+
+        Assert.assertNull(error);
+        Assert.assertNotNull(pass);
+
+        if (!getDesiredCapabilities().equals(
+                Browser.CHROME.getDesiredCapabilities())) {
+            WebElement html = driver.findElement(By.tagName("html"));
+            // reset zoom level back to 100%
+            html.sendKeys(Keys.chord(Keys.CONTROL, "0"));
+        }
+    }
+
+    private void openDebugExamineComponentHierarchyTab() {
+        WebElement button = findElement(By
+                .xpath("//button[@title='Examine component hierarchy']"));
+        // can't use 'click()' with zoom levels other than 100%
+        button.sendKeys(Keys.chord(Keys.SPACE));
+    }
+
+    private void clickDebugCheckLayoutsForPotentialProblems() {
+        WebElement button = findElement(By
+                .xpath("//button[@title='Check layouts for potential problems']"));
+
+        button.sendKeys(Keys.chord(Keys.SPACE));
+    }
+
+    private WebElement findLayoutAnalyzePassElement() {
+        try {
+            return findElement(By
+                    .xpath("//div[text()='Layouts analyzed, no top level problems']"));
+        } catch (NoSuchElementException e) {
+            return null;
+        }
+    }
+
+    private WebElement findLayoutAnalyzeAbortedElement() {
+        try {
+            return findElement(By
+                    .xpath("//div[text()='Aborting layout after 100 passess']"));
+        } catch (NoSuchElementException e) {
+            return null;
+        }
+    }
+}