Mac Picker UI: Screen Auto Selection

chrome/browser/ui/cocoa/media_picker/desktop_media_picker_controller.mm

 // Copyright 2013 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.
 
 #import "chrome/browser/ui/cocoa/media_picker/desktop_media_picker_controller.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 579 matching lines @@
 
 - (NSUInteger)numberOfItemsInImageBrowser:(IKImageBrowserView*)browser {
   DesktopMediaID::Type sourceType = [self sourceTypeForBrowser:browser];
   NSMutableArray* items = [self itemSetForType:sourceType];
   return [items count];
 }
 
 - (id)imageBrowser:(IKImageBrowserView*)browser itemAtIndex:(NSUInteger)index {
   DesktopMediaID::Type sourceType = [self sourceTypeForBrowser:browser];
   NSMutableArray* items = [self itemSetForType:sourceType];
-  return [items objectAtIndex:index];
+  id item = [items objectAtIndex:index];

[tapted, 2016/07/22 03:43:36]

id -> DesktopMediaPickerItem* (it's usually best to avoid duck-typing with `id`
when possible)

[qiangchen, 2016/07/22 18:33:54]

Done.

+  [item setTitleHidden:browser == screenBrowser_ && [items count] == 1];

[tapted, 2016/07/22 03:43:36]

this should have a comment - it's pretty subtle

[qiangchen, 2016/07/22 18:33:54]

Done.

+
+  return item;
 }
 
 #pragma mark IKImageBrowserDelegate
 
 - (void)imageBrowser:(IKImageBrowserView*)browser
     cellWasDoubleClickedAtIndex:(NSUInteger)index {
   DesktopMediaPickerItem* item;
   if (browser == screenBrowser_)
     item = [screenItems_ objectAtIndex:index];
   else
@@ skipping 63 matching lines @@
   NSInteger selectedIndex = [self selectedIndexForType:sourceType];
   if (selectedIndex >= index)
     ++selectedIndex;
 
   const DesktopMediaList::Source& source = list->GetSource(index);
   NSString* imageTitle = base::SysUTF16ToNSString(source.name);
   base::scoped_nsobject<DesktopMediaPickerItem> item(
       [[DesktopMediaPickerItem alloc] initWithSourceId:source.id
                                               imageUID:++lastImageUID_
                                             imageTitle:imageTitle]);
+
   [items insertObject:item atIndex:index];
   [browser reloadData];
-  if (sourceType == DesktopMediaID::TYPE_WEB_CONTENTS)
+  if (sourceType == DesktopMediaID::TYPE_WEB_CONTENTS) {
+    // Memorizing selection.
     [self setTabBrowserIndex:selectedIndex];
+  } else if (sourceType == DesktopMediaID::TYPE_SCREEN && [items count] == 1) {
+    // Preselect the first screen source.
+    [browser setSelectionIndexes:[NSIndexSet indexSetWithIndex:0]
+            byExtendingSelection:NO];
+  }
 
   NSString* autoselectSource = base::SysUTF8ToNSString(
       base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
           switches::kAutoSelectDesktopCaptureSource));
 
   if ([autoselectSource isEqualToString:imageTitle]) {
     [self reportResult:[item sourceID]];
     [self close];
   }
 }
@@ skipping 73 matching lines @@
 
   DesktopMediaPickerItem* item = [items objectAtIndex:index];
   [item setImageRepresentation:image];
   [browser reloadData];
 
   if (sourceType == DesktopMediaID::TYPE_WEB_CONTENTS)
     [self setTabBrowserIndex:selectedIndex];
 }
 
 @end  // @interface DesktopMediaPickerController