[WebPayments] Implement state transitions in desktop WebPayments dialog.

chrome/browser/ui/views/payments/payment_request_dialog.cc

 // Copyright 2016 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.
 
+#include "chrome/browser/ui/views/payments/payment_request_dialog.h"
+
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/payments/payment_request_impl.h"
-#include "chrome/browser/ui/views/payments/payment_request_dialog.h"
+#include "chrome/grit/generated_resources.h"
 #include "components/constrained_window/constrained_window_views.h"
 #include "content/public/browser/browser_thread.h"
+#include "ui/base/l10n/l10n_util.h"
+#include "ui/views/controls/button/md_text_button.h"
+#include "ui/views/controls/label.h"
 #include "ui/views/layout/fill_layout.h"
+#include "ui/views/layout/grid_layout.h"
+
+namespace {
+
+// The tag for the button that navigates back to the payment sheet.
+constexpr int kBackButtonTag = 0;
+
+// The tag for the button that navigates to the Order Summary sheet.
+constexpr int kOrderSummaryTag = 1;
+
+std::unique_ptr<views::View> CreateOrderSummaryView(
+    views::ButtonListener* button_listener) {
+  std::unique_ptr<views::View> view = base::MakeUnique<views::View>();
+
+  views::GridLayout* layout = new views::GridLayout(view.get());
+  view->SetLayoutManager(layout);
+  views::ColumnSet* columns = layout->AddColumnSet(0);
+  columns->AddColumn(views::GridLayout::TRAILING, views::GridLayout::CENTER,
+                     0, views::GridLayout::USE_PREF, 0, 0);
+
+  layout->StartRow(0, 0);
+  layout->AddView(new views::Label(
+      l10n_util::GetStringUTF16(IDS_PAYMENT_REQUEST_ORDER_SUMMARY_TITLE)));
+
+  layout->StartRow(0, 0);
+  views::LabelButton* back_button =
+      views::MdTextButton::CreateSecondaryUiBlueButton(
+          button_listener, base::ASCIIToUTF16("Back"));
+  back_button->set_tag(kBackButtonTag);
+  layout->AddView(back_button);
+
+  return view;
+}
+
+std::unique_ptr<views::View> CreatePaymentSheetView(
+    views::ButtonListener* button_listener) {
+  std::unique_ptr<views::View> view = base::MakeUnique<views::View>();
+
+  views::GridLayout* layout = new views::GridLayout(view.get());
+  view->SetLayoutManager(layout);
+  views::ColumnSet* columns = layout->AddColumnSet(0);
+  columns->AddColumn(views::GridLayout::TRAILING, views::GridLayout::CENTER,
+                     0, views::GridLayout::USE_PREF, 0, 0);
+
+  layout->StartRow(0, 0);
+  layout->AddView(new views::Label(
+      l10n_util::GetStringUTF16(IDS_PAYMENT_REQUEST_PAYMENT_SHEET_TITLE)));
+
+  layout->StartRow(0, 0);
+  views::LabelButton* order_summary_button =
+      views::MdTextButton::CreateSecondaryUiBlueButton(
+          button_listener, base::ASCIIToUTF16("Order Summary"));
+  order_summary_button->set_tag(kOrderSummaryTag);
+  layout->AddView(order_summary_button);
+
+  return view;
+}
+
+}  // namespace
 
 namespace chrome {
 
 void ShowPaymentRequestDialog(payments::PaymentRequestImpl* impl) {
-    constrained_window::ShowWebModalDialogViews(
-        new payments::PaymentRequestDialog(impl), impl->web_contents());
+  constrained_window::ShowWebModalDialogViews(
+      new payments::PaymentRequestDialog(impl), impl->web_contents());
 }
 
-}
+}  // namespace chrome
 
 namespace payments {
 
 PaymentRequestDialog::PaymentRequestDialog(PaymentRequestImpl* impl)
-    : impl_(impl),
-      label_(new views::Label(base::ASCIIToUTF16("Payments dialog"))) {
+    : impl_(impl) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   SetLayoutManager(new views::FillLayout());
-  AddChildView(label_.get());
+
+  view_stack_.set_owned_by_client();
+  AddChildView(&view_stack_);
+
+  ShowInitialPaymentSheet();
 }
 
 PaymentRequestDialog::~PaymentRequestDialog() {}
 
 ui::ModalType PaymentRequestDialog::GetModalType() const {
   return ui::MODAL_TYPE_CHILD;
 }
 
 gfx::Size PaymentRequestDialog::GetPreferredSize() const {
-  gfx::Size ps = label_->GetPreferredSize();
-  ps.Enlarge(200, 200);
-  return ps;
+  return gfx::Size(300, 300);
 }
 
 bool PaymentRequestDialog::Cancel() {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   impl_->Cancel();
   return true;
 }
 
+void PaymentRequestDialog::ShowInitialPaymentSheet() {
+  view_stack_.Push(CreatePaymentSheetView(this), false);
+}
+
+void PaymentRequestDialog::ShowOrderSummary() {
+  view_stack_.Push(CreateOrderSummaryView(this), true);
+}
+
+void PaymentRequestDialog::GoBack() {
+  view_stack_.Pop();
+}
+
+void PaymentRequestDialog::ButtonPressed(
+    views::Button* sender, const ui::Event& event) {
+  if (sender->tag() == kBackButtonTag) {
+    GoBack();
+  } else if (sender->tag() == kOrderSummaryTag) {
+    ShowOrderSummary();
+  }
+}
+
 }  // namespace payments