Derive possible heights after markForCheck() is called #3467 (#3479)

* fix(grid): add pipeTrigger in the AfterViewInit event #3467

* test(grid): add general test for treegrid default rendering #8347

* fix(grid): calling pipeTrigger is not needed #3467

* test(grid): move general test to component test file #3467

* test(grid): remove f from test file #3467

projects/igniteui-angular/src/lib/grids/grid-base.component.ts

@@ -2302,8 +2302,8 @@ export abstract class IgxGridBaseComponent extends DisplayDensityBase implements
         this.initColumns(this.columnList, (col: IgxColumnComponent) => this.onColumnInit.emit(col));
 
         this.columnListDiffer.diff(this.columnList);
-        this._derivePossibleHeight();
         this.markForCheck();
+        this._derivePossibleHeight();
 
         this.columnList.changes
             .pipe(takeUntil(this.destroy$))

projects/igniteui-angular/src/lib/grids/grid/grid.component.spec.ts

@@ -3063,7 +3063,7 @@ export class IgxGridTestComponent {
 
     public isVerticalScrollbarVisible() {
         const scrollbar = this.grid.verticalScrollContainer.getVerticalScroll();
-        if (scrollbar) {
+        if (scrollbar && scrollbar.offsetHeight > 0) {
             return scrollbar.offsetHeight < scrollbar.children[0].offsetHeight;
         }
         return false;

projects/igniteui-angular/src/lib/grids/tree-grid/tree-grid.component.spec.ts

@@ -0,0 +1,94 @@
+import { async, TestBed, fakeAsync, tick } from '@angular/core/testing';
+import { NoopAnimationsModule } from '@angular/platform-browser/animations';
+import { IgxTreeGridModule } from './index';
+import { IgxTreeGridComponent } from './tree-grid.component';
+import { DisplayDensity } from '../../core/displayDensity';
+import { configureTestSuite } from '../../test-utils/configure-suite';
+import { By } from '@angular/platform-browser';
+import { IgxTreeGridWrappedInContComponent } from '../../test-utils/tree-grid-components.spec';
+
+describe('IgxTreeGrid Component Tests', () => {
+
+    describe('IgxTreeGrid - default rendering for rows and columns', () => {
+        configureTestSuite();
+        let fix;
+        let grid: IgxTreeGridComponent;
+
+        beforeEach(async(() => {
+            TestBed.configureTestingModule({
+                declarations: [
+                    IgxTreeGridWrappedInContComponent
+                ],
+                imports: [
+                    NoopAnimationsModule, IgxTreeGridModule]
+            }).compileComponents();
+        }));
+
+        beforeEach(async(() => {
+            fix = TestBed.createComponent(IgxTreeGridWrappedInContComponent);
+            grid = fix.componentInstance.treeGrid;
+        }));
+
+        it('should match width and height of parent container when width/height are set in %', fakeAsync(() => {
+            fix.componentInstance.outerWidth = 800;
+            fix.componentInstance.outerHeight = 600;
+            grid.width = '50%';
+            grid.height = '50%';
+            tick();
+            fix.detectChanges();
+
+            expect(window.getComputedStyle(grid.nativeElement).height).toMatch('300px');
+            expect(window.getComputedStyle(grid.nativeElement).width).toMatch('400px');
+            expect(grid.rowList.length).toBeGreaterThan(0);
+        }));
+
+        it('should render 10 records if height is unset and parent container\'s height is unset', () => {
+            fix.detectChanges();
+            const defaultHeight = fix.debugElement.query(By.css('.igx-grid__tbody')).styles.height;
+            expect(defaultHeight).not.toBeNull();
+            expect(parseInt(defaultHeight, 10)).toBeGreaterThan(400);
+            expect(fix.componentInstance.isVerticalScrollbarVisible()).toBeTruthy();
+            expect(grid.rowList.length).toBeGreaterThanOrEqual(10);
+        });
+
+        it('should render 10 records if height is 100% and parent container\'s height is unset', fakeAsync(() => {
+            grid.height = '600px';
+            tick();
+            fix.detectChanges();
+            const defaultHeight = fix.debugElement.query(By.css('.igx-grid__tbody')).styles.height;
+            expect(defaultHeight).not.toBeNull();
+            expect(parseInt(defaultHeight, 10)).toBeGreaterThan(400);
+            expect(fix.componentInstance.isVerticalScrollbarVisible()).toBeTruthy();
+            expect(grid.rowList.length).toBeGreaterThanOrEqual(10);
+        }));
+
+        it(`should render all records exactly if height is 100% and parent container\'s height is unset and
+            there are fewer than 10 records in the data view`, fakeAsync(() => {
+                grid.height = '100%';
+                fix.componentInstance.data = fix.componentInstance.data.slice(0, 1);
+                tick();
+                fix.detectChanges();
+                const defaultHeight = fix.debugElement.query(By.css('.igx-grid__tbody')).styles.height;
+                expect(defaultHeight).not.toBeNull();
+                expect(parseInt(defaultHeight, 10)).toBeGreaterThan(200);
+                expect(fix.componentInstance.isVerticalScrollbarVisible()).toBeFalsy();
+                expect(grid.rowList.length).toEqual(6);
+        }));
+
+        it(`should render 11 records if height is 100% and parent container\'s height is unset and
+            display density is changed`, fakeAsync(() => {
+                grid.height = '100%';
+                fix.componentInstance.density = DisplayDensity.compact;
+                tick();
+                fix.detectChanges();
+                const defaultHeight = fix.debugElement.query(By.css('.igx-grid__tbody')).styles.height;
+                const defaultHeightNum = parseInt(defaultHeight, 10);
+                expect(defaultHeight).not.toBeNull();
+                expect(defaultHeightNum).toBeGreaterThan(300);
+                expect(defaultHeightNum).toBeLessThan(330);
+                expect(fix.componentInstance.isVerticalScrollbarVisible()).toBeTruthy();
+                expect(grid.rowList.length).toEqual(11);
+        }));
+    });
+
+});

projects/igniteui-angular/src/lib/test-utils/tree-grid-components.spec.ts

@@ -2,7 +2,7 @@ import { Component, ViewChild } from '@angular/core';
 import { IgxTreeGridComponent } from '../grids/tree-grid/tree-grid.component';
 import { SampleTestData } from './sample-test-data.spec';
 import { IgxNumberSummaryOperand, IgxSummaryResult } from '../grids';
-import { IgxTransactionService, IgxHierarchicalTransactionService } from '../../public_api';
+import { IgxTransactionService, IgxHierarchicalTransactionService, DisplayDensity } from '../../public_api';
 import { IgxGridTransaction } from '../grids/grid-base.component';
 
 @Component({
@@ -389,3 +389,55 @@ export class IgxTreeGridRowEditingHierarchicalDSTransactionComponent {
     @ViewChild('treeGrid', { read: IgxTreeGridComponent }) public treeGrid: IgxTreeGridComponent;
     public paging = false;
 }
+
+@Component({
+    template:
+        `<div [style.width.px]="outerWidth" [style.height.px]="outerHeight">
+            <igx-tree-grid #treeGrid [data]="data" [displayDensity]="density"
+                childDataKey="Employees" primaryKey="ID">
+                <igx-column [field]="'ID'" dataType="number"></igx-column>
+                <igx-column [field]="'Name'" dataType="string"></igx-column>
+                <igx-column [field]="'HireDate'" dataType="date"></igx-column>
+                <igx-column [field]="'Age'" dataType="number"></igx-column>
+        </igx-tree-grid>
+        </div>`
+})
+
+export class IgxTreeGridWrappedInContComponent {
+    @ViewChild(IgxTreeGridComponent) public treeGrid: IgxTreeGridComponent;
+    public data = SampleTestData.employeeTreeData();
+
+    public height = null;
+    public paging = false;
+    public pageSize = 5;
+    public density = DisplayDensity.comfortable;
+    public outerWidth = 800;
+    public outerHeight: number;
+
+    public isHorizontalScrollbarVisible() {
+        const scrollbar = this.treeGrid.parentVirtDir.getHorizontalScroll();
+        if (scrollbar) {
+            return scrollbar.offsetWidth < scrollbar.children[0].offsetWidth;
+        }
+
+        return false;
+    }
+
+    public getVerticalScrollHeight() {
+        const scrollbar = this.treeGrid.verticalScrollContainer.getVerticalScroll();
+        if (scrollbar) {
+            return parseInt(scrollbar.style.height, 10);
+        }
+
+        return 0;
+    }
+
+    public isVerticalScrollbarVisible() {
+        const scrollbar = this.treeGrid.verticalScrollContainer.getVerticalScroll();
+        if (scrollbar && scrollbar.offsetHeight > 0) {
+            return scrollbar.offsetHeight < scrollbar.children[0].offsetHeight;
+        }
+        return false;
+    }
+
+}