Implement default leading image behaviour in the omnibox.

Adds a default leading image to the omnibox to be used when
it's being focused (before the first update of the leading image).
There are two images: for the empty textfield (magnifying glass)
and the non-empty textfield (default favicon).

Bug: 865000
Cq-Include-Trybots: luci.chromium.try:ios-simulator-full-configs;master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: Ib9869c3b87f81041ec8a13b0ac220a3b93aa521e
Reviewed-on: https://chromium-review.googlesource.com/1146926Reviewed-by: Justin Cohen <justincohen@chromium.org>
Commit-Queue: Stepan Khapugin <stkhapugin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#577877}

ios/chrome/browser/ui/omnibox/omnibox_coordinator.mm

@@ -5,6 +5,7 @@
 #import "ios/chrome/browser/ui/omnibox/omnibox_coordinator.h"
 
 #include "base/logging.h"
+#include "base/strings/sys_string_conversions.h"
 #include "components/omnibox/browser/omnibox_edit_model.h"
 #include "components/strings/grit/components_strings.h"
 #include "ios/chrome/browser/browser_state/chrome_browser_state.h"
@@ -12,6 +13,7 @@
 #import "ios/chrome/browser/ui/location_bar/location_bar_constants.h"
 #import "ios/chrome/browser/ui/omnibox/omnibox_mediator.h"
 #import "ios/chrome/browser/ui/omnibox/omnibox_text_field_ios.h"
+#include "ios/chrome/browser/ui/omnibox/omnibox_util.h"
 #include "ios/chrome/browser/ui/omnibox/omnibox_view_controller.h"
 #include "ios/chrome/browser/ui/omnibox/omnibox_view_ios.h"
 #import "ios/chrome/browser/ui/omnibox/popup/omnibox_popup_coordinator.h"
@@ -54,6 +56,19 @@
 
   self.viewController =
       [[OmniboxViewController alloc] initWithIncognito:isIncognito];
+  std::string defaultLeadingImageName = GetResourceNameForAutocompleteMatchType(
+      AutocompleteMatchType::URL_WHAT_YOU_TYPED, /* is_starred */ false);
+  UIImage* defaultLeadingImage =
+      [[UIImage imageNamed:base::SysUTF8ToNSString(defaultLeadingImageName)]
+          imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
+  self.viewController.defaultLeadingImage = defaultLeadingImage;
+  std::string defaultEmptyOmniboxLeadingImageName =
+      GetResourceNameForAutocompleteMatchType(
+          AutocompleteMatchType::SEARCH_SUGGEST, /* is_starred */ false);
+  UIImage* defaultEmptyOmniboxLeadingImage = [[UIImage
+      imageNamed:base::SysUTF8ToNSString(defaultEmptyOmniboxLeadingImageName)]
+      imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
+  self.viewController.emptyTextLeadingImage = defaultEmptyOmniboxLeadingImage;
 
   self.viewController.dispatcher =
       static_cast<id<LoadQueryCommands, OmniboxFocuser>>(self.dispatcher);

ios/chrome/browser/ui/omnibox/omnibox_view_controller.h

@@ -21,6 +21,13 @@
 // The textfield used by this view controller.
 @property(nonatomic, readonly, strong) OmniboxTextFieldIOS* textField;
 
+// The default leading image to be used on omnibox focus before this is updated
+// via OmniboxConsumer protocol.
+@property(nonatomic, strong) UIImage* defaultLeadingImage;
+
+// The default leading image to be used whenever the omnibox text is empty.
+@property(nonatomic, strong) UIImage* emptyTextLeadingImage;
+
 // Designated initializer.
 - (instancetype)initWithIncognito:(BOOL)isIncognito;
 

ios/chrome/browser/ui/omnibox/omnibox_view_controller.mm

@@ -37,6 +37,8 @@ const CGFloat kClearButtonSize = 28.0f;
 @implementation OmniboxViewController
 @synthesize incognito = _incognito;
 @synthesize dispatcher = _dispatcher;
+@synthesize defaultLeadingImage = _defaultLeadingImage;
+@synthesize emptyTextLeadingImage = _emptyTextLeadingImage;
 @dynamic view;
 
 - (instancetype)initWithIncognito:(BOOL)isIncognito {
@@ -92,6 +94,11 @@ const CGFloat kClearButtonSize = 28.0f;
          selector:@selector(textFieldDidBeginEditing)
              name:UITextFieldTextDidBeginEditingNotification
            object:self.textField];
+  [[NSNotificationCenter defaultCenter]
+      addObserver:self
+         selector:@selector(textFieldDidChange)
+             name:UITextFieldTextDidChangeNotification
+           object:self.textField];
 }
 
 - (void)traitCollectionDidChange:(UITraitCollection*)previousTraitCollection {
@@ -135,6 +142,16 @@ const CGFloat kClearButtonSize = 28.0f;
 - (void)textFieldDidBeginEditing {
   // Update the clear button state.
   [self updateClearButtonVisibility];
+  [self.view setLeadingImage:self.textField.text.length
+                                 ? self.defaultLeadingImage
+                                 : self.emptyTextLeadingImage];
+}
+
+- (void)textFieldDidChange {
+  // If the text is empty, update the leading image.
+  if (self.textField.text.length == 0) {
+    [self.view setLeadingImage:self.emptyTextLeadingImage];
+  }
 }
 
 #pragma mark clear button
@@ -185,6 +202,7 @@ const CGFloat kClearButtonSize = 28.0f;
     // Calling setText: does not trigger UIControlEventEditingChanged, so update
     // the clear button visibility manually.
     [self updateClearButtonVisibility];
+    [self textFieldDidChange];
   }
 }