fix(material/autocomplete): reopen panel on input click

Currently if the user clicks an autocomplete to open it, selects an option and then clicks again, the panel won't open, because we use `focus` and the input was focused already. These changes add an extra `click` listener so the panel can reopen.

Fixes #15177.

Author: crisbeto

src/material-experimental/mdc-autocomplete/autocomplete-trigger.ts

@@ -41,6 +41,7 @@ export const MAT_AUTOCOMPLETE_VALUE_ACCESSOR: any = {
     '(blur)': '_onTouched()',
     '(input)': '_handleInput($event)',
     '(keydown)': '_handleKeydown($event)',
+    '(click)': 'openPanel()',
   },
   exportAs: 'matAutocompleteTrigger',
   providers: [MAT_AUTOCOMPLETE_VALUE_ACCESSOR],

src/material-experimental/mdc-autocomplete/autocomplete.spec.ts

@@ -569,6 +569,31 @@ describe('MDC-based MatAutocomplete', () => {
 
       expect(input.hasAttribute('aria-haspopup')).toBe(false);
     });
+
+    it('should close the panel when pressing escape', fakeAsync(() => {
+      const trigger = fixture.componentInstance.trigger;
+
+      input.focus();
+      flush();
+      fixture.detectChanges();
+
+      expect(document.activeElement).withContext('Expected input to be focused.').toBe(input);
+      expect(trigger.panelOpen).withContext('Expected panel to be open.').toBe(true);
+
+      trigger.closePanel();
+      fixture.detectChanges();
+
+      expect(document.activeElement)
+        .withContext('Expected input to continue to be focused.')
+        .toBe(input);
+      expect(trigger.panelOpen).withContext('Expected panel to be closed.').toBe(false);
+
+      input.click();
+      flush();
+      fixture.detectChanges();
+
+      expect(trigger.panelOpen).withContext('Expected panel to reopen on click.').toBe(true);
+    }));
   });
 
   it('should not close the panel when clicking on the input', fakeAsync(() => {

src/material/autocomplete/autocomplete-trigger.ts

@@ -245,8 +245,10 @@ export abstract class _MatAutocompleteTriggerBase
 
   /** Opens the autocomplete suggestion panel. */
   openPanel(): void {
-    this._attachOverlay();
-    this._floatLabel();
+    if (!this.panelOpen) {
+      this._attachOverlay();
+      this._floatLabel();
+    }
   }
 
   /** Closes the autocomplete suggestion panel. */
@@ -800,6 +802,7 @@ export abstract class _MatAutocompleteTriggerBase
     '(blur)': '_onTouched()',
     '(input)': '_handleInput($event)',
     '(keydown)': '_handleKeydown($event)',
+    '(click)': 'openPanel()',
   },
   exportAs: 'matAutocompleteTrigger',
   providers: [MAT_AUTOCOMPLETE_VALUE_ACCESSOR],

src/material/autocomplete/autocomplete.spec.ts

@@ -566,6 +566,31 @@ describe('MatAutocomplete', () => {
 
       expect(input.hasAttribute('aria-haspopup')).toBe(false);
     });
+
+    it('should close the panel when pressing escape', fakeAsync(() => {
+      const trigger = fixture.componentInstance.trigger;
+
+      input.focus();
+      flush();
+      fixture.detectChanges();
+
+      expect(document.activeElement).withContext('Expected input to be focused.').toBe(input);
+      expect(trigger.panelOpen).withContext('Expected panel to be open.').toBe(true);
+
+      trigger.closePanel();
+      fixture.detectChanges();
+
+      expect(document.activeElement)
+        .withContext('Expected input to continue to be focused.')
+        .toBe(input);
+      expect(trigger.panelOpen).withContext('Expected panel to be closed.').toBe(false);
+
+      input.click();
+      flush();
+      fixture.detectChanges();
+
+      expect(trigger.panelOpen).withContext('Expected panel to reopen on click.').toBe(true);
+    }));
   });
 
   it('should not close the panel when clicking on the input', fakeAsync(() => {