Add server-side expand and collapse to TreeGrid (#9021)

* Add server-side expand and collapse to TreeGrid

* Add javadocs

* Fix variable naming in TreeGridHugeTreeTest

* Fix review comments

* Merge remote-tracking branch 'github/master' into 8759-server-expand

* Clear pending expands when all data is dropped

* Add documentation

4 files changed, 254 insertions, 27 deletions

diff --git a/uitest/src/main/java/com/vaadin/tests/components/treegrid/TreeGridBasicFeatures.java b/uitest/src/main/java/com/vaadin/tests/components/treegrid/TreeGridBasicFeatures.java
index ae011355c9..a8ce0a7489 100644
--- a/uitest/src/main/java/com/vaadin/tests/components/treegrid/TreeGridBasicFeatures.java
+++ b/uitest/src/main/java/com/vaadin/tests/components/treegrid/TreeGridBasicFeatures.java
@@ -63,6 +63,8 @@ public class TreeGridBasicFeatures extends AbstractComponentTest<TreeGrid> {
         createDataProviderSelect();
         createHierarchyColumnSelect();
         createCollapseAllowedSelect();
+        createExpandMenu();
+        createCollapseMenu();
         createListenerMenu();
     }
 
@@ -146,13 +148,45 @@ public class TreeGridBasicFeatures extends AbstractComponentTest<TreeGrid> {
     }
 
     @SuppressWarnings("unchecked")
+    private void createExpandMenu() {
+        createCategory("Server-side expand", CATEGORY_FEATURES);
+        createClickAction("Expand 0 | 0", "Server-side expand",
+                (treeGrid, value, data) -> treeGrid.expand(value),
+                new HierarchicalTestBean(null, 0, 0));
+        createClickAction("Expand 1 | 1", "Server-side expand",
+                (treeGrid, value, data) -> treeGrid.expand(value),
+                new HierarchicalTestBean("/0/0", 1, 1));
+        createClickAction("Expand 2 | 1", "Server-side expand",
+                (treeGrid, value, data) -> treeGrid.expand(value),
+                new HierarchicalTestBean("/0/0/1/1", 2, 1));
+    }
+
+    @SuppressWarnings("unchecked")
+    private void createCollapseMenu() {
+        createCategory("Server-side collapse", CATEGORY_FEATURES);
+        createClickAction("Collapse 0 | 0", "Server-side collapse",
+                (treeGrid, value, data) -> treeGrid.collapse(value),
+                new HierarchicalTestBean(null, 0, 0));
+        createClickAction("Collapse 1 | 1", "Server-side collapse",
+                (treeGrid, value, data) -> treeGrid.collapse(value),
+                new HierarchicalTestBean("/0/0", 1, 1));
+        createClickAction("Collapse 2 | 1", "Server-side collapse",
+                (treeGrid, value, data) -> treeGrid.collapse(value),
+                new HierarchicalTestBean("/0/0/1/1", 2, 1));
+    }
+
+    @SuppressWarnings("unchecked")
     private void createListenerMenu() {
         createListenerAction("Collapse listener", "State",
                 treeGrid -> treeGrid.addCollapseListener(event -> log(
-                        "Item collapsed: " + event.getCollapsedItem())));
+                        "Item collapsed (user originated: "
+                                + event.isUserOriginated() + "): "
+                                + event.getCollapsedItem())));
         createListenerAction("Expand listener", "State",
                 treeGrid -> treeGrid.addExpandListener(event -> log(
-                        "Item expanded: " + event.getExpandedItem())));
+                        "Item expanded (user originated: "
+                                + event.isUserOriginated() + "): "
+                                + event.getExpandedItem())));
     }
 
     static class HierarchicalTestBean {
diff --git a/uitest/src/main/java/com/vaadin/tests/components/treegrid/TreeGridHugeTree.java b/uitest/src/main/java/com/vaadin/tests/components/treegrid/TreeGridHugeTree.java
new file mode 100644
index 0000000000..7cfb926849
--- /dev/null
+++ b/uitest/src/main/java/com/vaadin/tests/components/treegrid/TreeGridHugeTree.java
@@ -0,0 +1,57 @@
+package com.vaadin.tests.components.treegrid;
+
+import com.vaadin.annotations.Theme;
+import com.vaadin.annotations.Widgetset;
+import com.vaadin.data.HierarchyData;
+import com.vaadin.data.provider.InMemoryHierarchicalDataProvider;
+import com.vaadin.server.VaadinRequest;
+import com.vaadin.tests.components.AbstractTestUI;
+import com.vaadin.ui.Button;
+import com.vaadin.ui.TreeGrid;
+
+@Theme("valo")
+@Widgetset("com.vaadin.DefaultWidgetSet")
+public class TreeGridHugeTree
+        extends AbstractTestUI {
+
+    private TreeGrid<String> treeGrid;
+    private InMemoryHierarchicalDataProvider<String> inMemoryDataProvider;
+
+    private void initializeDataProvider() {
+        HierarchyData<String> data = new HierarchyData<>();
+        for (int i = 0; i < 3; i++) {
+            String granddad = "Granddad " + i;
+            data.addItem(null, granddad);
+            for (int j = 0; j < 3; j++) {
+                String dad = "Dad " + i + "/" + j;
+                data.addItem(granddad, dad);
+                for (int k = 0; k < 300; k++) {
+                    String son = "Son " + i + "/" + j + "/" + k;
+                    data.addItem(dad, son);
+                }
+            }
+        }
+        inMemoryDataProvider = new InMemoryHierarchicalDataProvider<>(data);
+    }
+
+    @Override
+    protected void setup(VaadinRequest request) {
+        initializeDataProvider();
+        treeGrid = new TreeGrid<>();
+        treeGrid.setDataProvider(inMemoryDataProvider);
+        treeGrid.setSizeFull();
+        treeGrid.addColumn(String::toString).setCaption("String")
+                .setId("string");
+        treeGrid.addColumn((i) -> "--").setCaption("Nothing");
+        treeGrid.setHierarchyColumn("string");
+        treeGrid.setId("testComponent");
+
+        Button expand = new Button("Expand Granddad 1");
+        expand.addClickListener(event -> treeGrid.expand("Granddad 1"));
+        Button collapse = new Button("Collapse Granddad 1");
+        collapse.addClickListener(event -> treeGrid.collapse("Granddad 1"));
+
+        addComponents(treeGrid, expand, collapse);
+    }
+
+}
\ No newline at end of file
diff --git a/uitest/src/test/java/com/vaadin/tests/components/treegrid/TreeGridBasicFeaturesTest.java b/uitest/src/test/java/com/vaadin/tests/components/treegrid/TreeGridBasicFeaturesTest.java
index 7fb7ddf3f3..dd4546c6c0 100644
--- a/uitest/src/test/java/com/vaadin/tests/components/treegrid/TreeGridBasicFeaturesTest.java
+++ b/uitest/src/test/java/com/vaadin/tests/components/treegrid/TreeGridBasicFeaturesTest.java
@@ -1,12 +1,13 @@
 package com.vaadin.tests.components.treegrid;
 
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
 import java.util.Arrays;
 import java.util.Collection;
-import java.util.List;
 
-import com.vaadin.testbench.parallel.Browser;
 import org.junit.Before;
-import org.junit.Ignore;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.Parameterized.Parameters;
@@ -18,10 +19,6 @@ import com.vaadin.testbench.elements.TreeGridElement;
 import com.vaadin.tests.tb3.MultiBrowserTest;
 import com.vaadin.tests.tb3.ParameterizedTB3Runner;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
-
 @RunWith(ParameterizedTB3Runner.class)
 public class TreeGridBasicFeaturesTest extends MultiBrowserTest {
 
@@ -41,28 +38,82 @@ public class TreeGridBasicFeaturesTest extends MultiBrowserTest {
     @Before
     public void before() {
         setDebug(true);
-        openTestURL("theme=valo");
+        openTestURL();
         grid = $(TreeGridElement.class).first();
     }
 
     @Test
-    @Ignore // currently no implementation exists for toggling from the server
-            // side
     public void toggle_collapse_server_side() {
         assertEquals(3, grid.getRowCount());
         assertCellTexts(0, 0, new String[] { "0 | 0", "0 | 1", "0 | 2" });
 
-        selectMenuPath("Component", "Features", "Toggle expand", "0 | 0");
+        selectMenuPath("Component", "Features", "Server-side expand",
+                "Expand 0 | 0");
+        assertEquals(6, grid.getRowCount());
+        assertCellTexts(1, 0, new String[] { "1 | 0", "1 | 1", "1 | 2" });
+
+        // expanding already expanded item should have no effect
+        selectMenuPath("Component", "Features", "Server-side expand",
+                "Expand 0 | 0");
         assertEquals(6, grid.getRowCount());
         assertCellTexts(1, 0, new String[] { "1 | 0", "1 | 1", "1 | 2" });
 
-        selectMenuPath("Component", "Features", "Toggle expand", "0 | 0");
+        selectMenuPath("Component", "Features", "Server-side collapse",
+                "Collapse 0 | 0");
+        assertEquals(3, grid.getRowCount());
+        assertCellTexts(0, 0, new String[] { "0 | 0", "0 | 1", "0 | 2" });
+
+        // collapsing the same item twice should have no effect
+        selectMenuPath("Component", "Features", "Server-side collapse",
+                "Collapse 0 | 0");
+        assertEquals(3, grid.getRowCount());
+        assertCellTexts(0, 0, new String[] { "0 | 0", "0 | 1", "0 | 2" });
+
+        selectMenuPath("Component", "Features", "Server-side expand",
+                "Expand 1 | 1");
+        // 1 | 1 not yet visible, shouldn't immediately expand anything
         assertEquals(3, grid.getRowCount());
         assertCellTexts(0, 0, new String[] { "0 | 0", "0 | 1", "0 | 2" });
 
+        selectMenuPath("Component", "Features", "Server-side expand",
+                "Expand 0 | 0");
+        // 1 | 1 becomes visible and is also expanded
+        assertEquals(9, grid.getRowCount());
+        assertCellTexts(1, 0, new String[] { "1 | 0", "1 | 1", "2 | 0", "2 | 1",
+                "2 | 2", "1 | 2" });
+
         // collapsing a leaf should have no effect
-        selectMenuPath("Component", "Features", "Toggle expand", "1 | 0");
+        selectMenuPath("Component", "Features", "Server-side collapse",
+                "Collapse 2 | 1");
+        assertEquals(9, grid.getRowCount());
+        assertCellTexts(1, 0, new String[] { "1 | 0", "1 | 1", "2 | 0", "2 | 1",
+                "2 | 2", "1 | 2" });
+
+        // collapsing 0 | 0 should collapse the expanded 1 | 1
+        selectMenuPath("Component", "Features", "Server-side collapse",
+                "Collapse 0 | 0");
         assertEquals(3, grid.getRowCount());
+        assertCellTexts(0, 0, new String[] { "0 | 0", "0 | 1", "0 | 2" });
+
+        // 1 | 1 should not be expanded this time
+        selectMenuPath("Component", "Features", "Server-side expand",
+                "Expand 0 | 0");
+        assertEquals(6, grid.getRowCount());
+        assertCellTexts(1, 0, new String[] { "1 | 0", "1 | 1", "1 | 2" });
+
+        assertNoSystemNotifications();
+        assertNoErrorNotifications();
+    }
+
+    @Test
+    public void pending_expands_cleared_when_data_provider_set() {
+        selectMenuPath("Component", "Features", "Server-side expand",
+                "Expand 1 | 1");
+        selectMenuPath("Component", "Features", "Set data provider",
+                "LazyHierarchicalDataProvider");
+        grid.expandWithClick(0);
+        assertEquals(6, grid.getRowCount());
+        assertCellTexts(1, 0, new String[] { "1 | 0", "1 | 1", "1 | 2" });
     }
 
     @Test
@@ -105,20 +156,21 @@ public class TreeGridBasicFeaturesTest extends MultiBrowserTest {
         // Should expand "1 | 1" without moving focus
         new Actions(getDriver()).sendKeys(Keys.RIGHT).perform();
         assertEquals(9, grid.getRowCount());
-        assertCellTexts(2, 0, new String[] { "1 | 1", "2 | 0",  "2 | 1",  "2 | 2",  "1 | 2"});
+        assertCellTexts(2, 0,
+                new String[] { "1 | 1", "2 | 0", "2 | 1", "2 | 2", "1 | 2" });
         assertTrue(grid.getRow(2).hasClassName("v-grid-rowmode-row-focused"));
 
         // Should collapse "1 | 1"
         new Actions(getDriver()).sendKeys(Keys.LEFT).perform();
         assertEquals(6, grid.getRowCount());
-        assertCellTexts(2, 0, new String[] { "1 | 1", "1 | 2",  "0 | 1"});
+        assertCellTexts(2, 0, new String[] { "1 | 1", "1 | 2", "0 | 1" });
         assertTrue(grid.getRow(2).hasClassName("v-grid-rowmode-row-focused"));
 
-
         // Should navigate to "0 | 0"
         new Actions(getDriver()).sendKeys(Keys.LEFT).perform();
         assertEquals(6, grid.getRowCount());
-        assertCellTexts(0, 0, new String[] { "0 | 0", "1 | 0", "1 | 1", "1 | 2" , "0 | 1" });
+        assertCellTexts(0, 0,
+                new String[] { "0 | 0", "1 | 0", "1 | 1", "1 | 2", "0 | 1" });
         assertTrue(grid.getRow(0).hasClassName("v-grid-rowmode-row-focused"));
 
         // Should collapse "0 | 0"
@@ -171,18 +223,40 @@ public class TreeGridBasicFeaturesTest extends MultiBrowserTest {
         selectMenuPath("Component", "State", "Expand listener");
         selectMenuPath("Component", "State", "Collapse listener");
 
-        assertFalse(logContainsText("Item expanded: 0 | 0"));
-        assertFalse(logContainsText("Item collapsed: 0 | 0"));
+        assertFalse(logContainsText(
+                "Item expanded (user originated: true): 0 | 0"));
+        assertFalse(logContainsText(
+                "Item collapsed (user originated: true): 0 | 0"));
 
         grid.expandWithClick(0);
 
-        assertTrue(logContainsText("Item expanded: 0 | 0"));
-        assertFalse(logContainsText("Item collapsed: 0 | 0"));
+        assertTrue(logContainsText(
+                "Item expanded (user originated: true): 0 | 0"));
+        assertFalse(logContainsText(
+                "Item collapsed (user originated: true): 0 | 0"));
 
         grid.collapseWithClick(0);
 
-        assertTrue(logContainsText("Item expanded: 0 | 0"));
-        assertTrue(logContainsText("Item collapsed: 0 | 0"));
+        assertTrue(logContainsText(
+                "Item expanded (user originated: true): 0 | 0"));
+        assertTrue(logContainsText(
+                "Item collapsed (user originated: true): 0 | 0"));
+
+        selectMenuPath("Component", "Features", "Server-side expand",
+                "Expand 0 | 0");
+
+        assertTrue(logContainsText(
+                "Item expanded (user originated: false): 0 | 0"));
+        assertFalse(logContainsText(
+                "Item collapsed (user originated: false): 0 | 0"));
+
+        selectMenuPath("Component", "Features", "Server-side collapse",
+                "Collapse 0 | 0");
+
+        assertTrue(logContainsText(
+                "Item expanded (user originated: false): 0 | 0"));
+        assertTrue(logContainsText(
+                "Item collapsed (user originated: false): 0 | 0"));
 
         selectMenuPath("Component", "State", "Expand listener");
         selectMenuPath("Component", "State", "Collapse listener");
@@ -190,8 +264,10 @@ public class TreeGridBasicFeaturesTest extends MultiBrowserTest {
         grid.expandWithClick(1);
         grid.collapseWithClick(1);
 
-        assertFalse(logContainsText("Item expanded: 0 | 1"));
-        assertFalse(logContainsText("Item collapsed: 0 | 1"));
+        assertFalse(logContainsText(
+                "Item expanded (user originated: true): 0 | 1"));
+        assertFalse(logContainsText(
+                "Item collapsed (user originated: true): 0 | 1"));
     }
 
     private void assertCellTexts(int startRowIndex, int cellIndex,
diff --git a/uitest/src/test/java/com/vaadin/tests/components/treegrid/TreeGridHugeTreeTest.java b/uitest/src/test/java/com/vaadin/tests/components/treegrid/TreeGridHugeTreeTest.java
new file mode 100644
index 0000000000..1d5d9b309d
--- /dev/null
+++ b/uitest/src/test/java/com/vaadin/tests/components/treegrid/TreeGridHugeTreeTest.java
@@ -0,0 +1,60 @@
+package com.vaadin.tests.components.treegrid;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import com.vaadin.testbench.elements.ButtonElement;
+import com.vaadin.testbench.elements.TreeGridElement;
+import com.vaadin.tests.tb3.SingleBrowserTest;
+
+public class TreeGridHugeTreeTest extends SingleBrowserTest {
+
+    private TreeGridElement grid;
+
+    @Test
+    public void toggle_expand_when_row_out_of_cache() {
+        openTestURL();
+
+        grid = $(TreeGridElement.class).first();
+        ButtonElement expandSecondRowButton = $(ButtonElement.class).get(0);
+        ButtonElement collapseSecondRowButton = $(ButtonElement.class).get(1);
+
+        grid.expandWithClick(2);
+        grid.expandWithClick(3);
+        grid.scrollToRow(300);
+        grid.waitForVaadin();
+
+        expandSecondRowButton.click();
+
+        grid.scrollToRow(0);
+        assertCellTexts(0, 0, new String[] { "Granddad 0", "Granddad 1",
+                "Dad 1/0", "Dad 1/1", "Dad 1/2", "Granddad 2", "Dad 2/0" });
+
+        grid.scrollToRow(300);
+        grid.waitForVaadin();
+        collapseSecondRowButton.click();
+        grid.scrollToRow(0);
+        grid.waitForVaadin();
+        assertCellTexts(0, 0, new String[] { "Granddad 0", "Granddad 1",
+                "Granddad 2", "Dad 2/0" });
+
+        grid.scrollToRow(300);
+        grid.waitForVaadin();
+        expandSecondRowButton.click();
+        collapseSecondRowButton.click();
+        grid.scrollToRow(0);
+        grid.waitForVaadin();
+        assertCellTexts(0, 0, new String[] { "Granddad 0", "Granddad 1",
+                "Granddad 2", "Dad 2/0" });
+    }
+
+    private void assertCellTexts(int startRowIndex, int cellIndex,
+            String[] cellTexts) {
+        int index = startRowIndex;
+        for (String cellText : cellTexts) {
+            Assert.assertEquals(cellText,
+                    grid.getRow(index).getCell(cellIndex).getText());
+            index++;
+        }
+    }
+}