[Payments] Add error messages to credit card editor.

chrome/browser/ui/views/payments/editor_view_controller.h

 // Copyright 2017 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 CHROME_BROWSER_UI_VIEWS_PAYMENTS_EDITOR_VIEW_CONTROLLER_H_
 #define CHROME_BROWSER_UI_VIEWS_PAYMENTS_EDITOR_VIEW_CONTROLLER_H_
 
 #include <memory>
+#include <tuple>
 #include <unordered_map>
 #include <vector>
 
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/strings/string16.h"
 #include "chrome/browser/ui/views/payments/payment_request_sheet_controller.h"
 #include "chrome/browser/ui/views/payments/validation_delegate.h"
 #include "components/autofill/core/browser/field_types.h"
 #include "ui/views/controls/button/vector_icon_button_delegate.h"
 #include "ui/views/controls/combobox/combobox_listener.h"
 #include "ui/views/controls/textfield/textfield_controller.h"
 #include "ui/views/view.h"
 
 namespace ui {
 class ComboboxModel;
 }
 
 namespace views {
+class GridLayout;
+class Label;
 class Textfield;
 class View;
 }  // namespace views
 
 namespace payments {
 
 class PaymentRequest;
 class PaymentRequestDialogView;
 class ValidatingCombobox;
 class ValidatingTextfield;
 
 // Field definition for an editor field, used to build the UI.
 struct EditorField {
   enum class LengthHint : int { HINT_LONG, HINT_SHORT };
   enum class ControlType : int { TEXTFIELD, COMBOBOX };
 
   EditorField(autofill::ServerFieldType type,
               const base::string16& label,
               LengthHint length_hint,
               bool required,
               ControlType control_type = ControlType::TEXTFIELD)
       : type(type),
         label(label),
         length_hint(length_hint),
         required(required),
         control_type(control_type) {}
 
+  struct Compare {
+    bool operator()(const EditorField& lhs, const EditorField& rhs) const {
+      return std::tie(lhs.type, lhs.label) < std::tie(rhs.type, rhs.label);
+    }
+  };
+
   // Data type in the field.
   const autofill::ServerFieldType type;
   // Label to be shown alongside the field.
   const base::string16 label;
   // Hint about the length of this field's contents.
   LengthHint length_hint;
   // Whether the field is required.
   bool required;
   // The control type.
   ControlType control_type;
 };
 
 // The PaymentRequestSheetController subtype for the editor screens of the
 // Payment Request flow.
 class EditorViewController : public PaymentRequestSheetController,
                              public views::TextfieldController,
                              public views::ComboboxListener {
  public:
   using TextFieldsMap =
       std::unordered_map<ValidatingTextfield*, const EditorField>;
   using ComboboxMap =
       std::unordered_map<ValidatingCombobox*, const EditorField>;
+  using ErrorLabelMap =
+      std::map<const EditorField, views::Label*, EditorField::Compare>;
 
   // Does not take ownership of the arguments, which should outlive this object.
   EditorViewController(PaymentRequest* request,
                        PaymentRequestDialogView* dialog);
   ~EditorViewController() override;
 
   // PaymentRequestSheetController:
   std::unique_ptr<views::View> CreateView() override;
   std::unique_ptr<views::View> CreateLeadingFooterView() override;
 
   virtual std::unique_ptr<views::View> CreateHeaderView() = 0;
   // Returns the field definitions used to build the UI.
   virtual std::vector<EditorField> GetFieldDefinitions() = 0;
   // Validates the data entered and attempts to save; returns true on success.
   virtual bool ValidateModelAndSave() = 0;
   // Creates a ValidationDelegate which knows how to validate for a given
-  // |field| definition.
+  // |field| definition. A reference to this |controller| is provided and should
+  // outlive the delegate.
   virtual std::unique_ptr<ValidationDelegate> CreateValidationDelegate(

[anthonyvd, 2017/02/22 19:32:45]

Why not just use |this| in the function body instead of passing |this| as a
param?

[Mathieu, 2017/02/22 20:08:59]

Doh!

-      const EditorField& field) = 0;
+      const EditorField& field,
+      EditorViewController* controller) = 0;
   virtual std::unique_ptr<ui::ComboboxModel> GetComboboxModelForType(
       const autofill::ServerFieldType& type) = 0;
 
+  // Will display |error_message| alongside the input field represented by
+  // |field|.
+  void DisplayErrorMessageForField(const EditorField& field,
+                                   const base::string16& error_message);
+
   const ComboboxMap& comboboxes() const { return comboboxes_; }
   const TextFieldsMap& text_fields() const { return text_fields_; }
 
  protected:
   // PaymentRequestSheetController;
   std::unique_ptr<views::Button> CreatePrimaryButton() override;
 
  private:
   // PaymentRequestSheetController:
   void ButtonPressed(views::Button* sender, const ui::Event& event) override;
 
   // views::TextfieldController:
   void ContentsChanged(views::Textfield* sender,
                        const base::string16& new_contents) override;
 
   // views::ComboboxListener:
   void OnPerformAction(views::Combobox* combobox) override;
 
-  // Creates a view for an input field to be added in the editor sheet. |field|
-  // is the field definition, which contains the label and the hint about
-  // the length of the input field.
-  std::unique_ptr<views::View> CreateInputField(const EditorField& field);
+  // Creates the whole editor view to go within the editor dialog. It
+  // encompasses all the input fields created by CreateInputField().
+  std::unique_ptr<views::View> CreateEditorView();
+
+  // Adds some views to |layout|, to represent an input field and its labels.
+  // |field| is the field definition, which contains the label and the hint
+  // about the length of the input field. A placeholder error label is also
+  // added (see implementation).
+  void CreateInputField(views::GridLayout* layout, const EditorField& field);
 
   // Used to remember the association between the input field UI element and the
   // original field definition. The ValidatingTextfield* and ValidatingCombobox*
   // are owned by their parent view, this only keeps a reference that is good as
   // long as the input field is visible.
   TextFieldsMap text_fields_;
   ComboboxMap comboboxes_;
+  // Tracks the relationship between a field and its error label.
+  ErrorLabelMap error_labels_;
 
   DISALLOW_COPY_AND_ASSIGN(EditorViewController);
 };
 
 }  // namespace payments
 
 #endif  // CHROME_BROWSER_UI_VIEWS_PAYMENTS_EDITOR_VIEW_CONTROLLER_H_