Create base class for AssistantUiElement views.

This is part of a multi-CL effort to clean up the AssistantUiElement
modeling/rendering pipeline. Once complete, UiElementContainerView will
only know about AssistantUiElementViews, not inheriting subclasses.

More details in the bug.

Bug: b:145003512
Change-Id: I6b9b96af2f7f7e73a19785d58104049f287616df
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1953700
Commit-Queue: David Black <dmblack@google.com>
Reviewed-by: Xiaohui Chen <xiaohuic@chromium.org>
Cr-Commit-Position: refs/heads/master@{#726629}

ash/assistant/ui/BUILD.gn

@@ -89,6 +89,7 @@ component("ui") {
     "main_stage/assistant_query_view.h",
     "main_stage/assistant_text_element_view.cc",
     "main_stage/assistant_text_element_view.h",
+    "main_stage/assistant_ui_element_view.h",
     "main_stage/element_animator.cc",
     "main_stage/element_animator.h",
     "main_stage/suggestion_chip_view.cc",

ash/assistant/ui/main_stage/assistant_card_element_view.h

@@ -5,11 +5,11 @@
 #ifndef ASH_ASSISTANT_UI_MAIN_STAGE_ASSISTANT_CARD_ELEMENT_VIEW_H_
 #define ASH_ASSISTANT_UI_MAIN_STAGE_ASSISTANT_CARD_ELEMENT_VIEW_H_
 
+#include "ash/assistant/ui/main_stage/assistant_ui_element_view.h"
 #include "base/component_export.h"
 #include "base/macros.h"
 #include "services/content/public/cpp/navigable_contents.h"
 #include "services/content/public/cpp/navigable_contents_view.h"
-#include "ui/views/view.h"
 
 namespace ash {
 
@@ -19,14 +19,14 @@ class AssistantViewDelegate;
 // AssistantCardElementView is the visual representation of an
 // AssistantCardElement. It is a child view of UiElementContainerView.
 class COMPONENT_EXPORT(ASSISTANT_UI) AssistantCardElementView
-    : public views::View,
+    : public AssistantUiElementView,
       public content::NavigableContentsObserver {
  public:
   AssistantCardElementView(AssistantViewDelegate* delegate,
                            const AssistantCardElement* card_element);
   ~AssistantCardElementView() override;
 
-  // views::View:
+  // AssistantUiElementView:
   const char* GetClassName() const override;
   void AddedToWidget() override;
   void ChildPreferredSizeChanged(views::View* child) override;

ash/assistant/ui/main_stage/assistant_text_element_view.cc

@@ -4,26 +4,22 @@
 
 #include "ash/assistant/ui/main_stage/assistant_text_element_view.h"
 
+#include <memory>
+
 #include "ash/assistant/model/ui/assistant_text_element.h"
 #include "ash/assistant/ui/assistant_ui_constants.h"
 #include "base/strings/utf_string_conversions.h"
 #include "ui/views/background.h"
+#include "ui/views/controls/label.h"
+#include "ui/views/layout/fill_layout.h"
 
 namespace ash {
 
 // AssistantTextElementView ----------------------------------------------------
 
 AssistantTextElementView::AssistantTextElementView(
-    const AssistantTextElement* text_element)
-    : views::Label(base::UTF8ToUTF16(text_element->text())) {
-  SetAutoColorReadabilityEnabled(false);
-  SetEnabledColor(kTextColorPrimary);
-  SetFontList(assistant::ui::GetDefaultFontList()
-                  .DeriveWithSizeDelta(2)
-                  .DeriveWithWeight(gfx::Font::Weight::MEDIUM));
-  SetHorizontalAlignment(gfx::HorizontalAlignment::ALIGN_LEFT);
-  SetMultiLine(true);
-  SetBackground(views::CreateSolidBackground(SK_ColorWHITE));
+    const AssistantTextElement* text_element) {
+  InitLayout(text_element);
 }
 
 AssistantTextElementView::~AssistantTextElementView() = default;
@@ -32,4 +28,25 @@ const char* AssistantTextElementView::GetClassName() const {
   return "AssistantTextElementView";
 }
 
+void AssistantTextElementView::ChildPreferredSizeChanged(views::View* child) {
+  PreferredSizeChanged();
+}
+
+void AssistantTextElementView::InitLayout(
+    const AssistantTextElement* text_element) {
+  SetLayoutManager(std::make_unique<views::FillLayout>());
+
+  // Label.
+  views::Label* label = AddChildView(
+      std::make_unique<views::Label>(base::UTF8ToUTF16(text_element->text())));
+  label->SetAutoColorReadabilityEnabled(false);
+  label->SetBackground(views::CreateSolidBackground(SK_ColorWHITE));
+  label->SetEnabledColor(kTextColorPrimary);
+  label->SetFontList(assistant::ui::GetDefaultFontList()
+                         .DeriveWithSizeDelta(2)
+                         .DeriveWithWeight(gfx::Font::Weight::MEDIUM));
+  label->SetHorizontalAlignment(gfx::HorizontalAlignment::ALIGN_LEFT);
+  label->SetMultiLine(true);
+}
+
 }  // namespace ash

ash/assistant/ui/main_stage/assistant_text_element_view.h

@@ -5,9 +5,9 @@
 #ifndef ASH_ASSISTANT_UI_MAIN_STAGE_ASSISTANT_TEXT_ELEMENT_VIEW_H_
 #define ASH_ASSISTANT_UI_MAIN_STAGE_ASSISTANT_TEXT_ELEMENT_VIEW_H_
 
+#include "ash/assistant/ui/main_stage/assistant_ui_element_view.h"
 #include "base/component_export.h"
 #include "base/macros.h"
-#include "ui/views/controls/label.h"
 
 namespace ash {
 
@@ -16,15 +16,18 @@ class AssistantTextElement;
 // AssistantTextElementView is the visual representation of an
 // AssistantTextElement. It is a child view of UiElementContainerView.
 class COMPONENT_EXPORT(ASSISTANT_UI) AssistantTextElementView
-    : public views::Label {
+    : public AssistantUiElementView {
  public:
   explicit AssistantTextElementView(const AssistantTextElement* text_element);
   ~AssistantTextElementView() override;
 
-  // views::Label:
+  // AssistantUiElementView:
   const char* GetClassName() const override;
+  void ChildPreferredSizeChanged(views::View* child) override;
 
  private:
+  void InitLayout(const AssistantTextElement* text_element);
+
   DISALLOW_COPY_AND_ASSIGN(AssistantTextElementView);
 };
 

ash/assistant/ui/main_stage/assistant_ui_element_view.h

+// Copyright 2018 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef ASH_ASSISTANT_UI_MAIN_STAGE_ASSISTANT_UI_ELEMENT_VIEW_H_
+#define ASH_ASSISTANT_UI_MAIN_STAGE_ASSISTANT_UI_ELEMENT_VIEW_H_
+
+#include "base/component_export.h"
+#include "ui/views/view.h"
+
+namespace ash {
+
+// Base class for a visual representation of an AssistantUiElement. It is a
+// child view of UiElementContainerView.
+class COMPONENT_EXPORT(ASSISTANT_UI) AssistantUiElementView
+    : public views::View {
+ public:
+  explicit AssistantUiElementView(AssistantUiElementView& copy) = delete;
+  AssistantUiElementView& operator=(AssistantUiElementView& assign) = delete;
+  ~AssistantUiElementView() override = default;
+
+ protected:
+  AssistantUiElementView() = default;
+};
+
+}  // namespace ash
+
+#endif  // ASH_ASSISTANT_UI_MAIN_STAGE_ASSISTANT_UI_ELEMENT_VIEW_H_