Switching Clank to use direction-based selection granularity strategy and adding a chrome flag.

chrome/browser/about_flags.cc

 // Copyright (c) 2012 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/about_flags.h"
 
 #include <iterator>
 #include <map>
 #include <set>
 #include <utility>
@@ skipping 160 matching lines @@
   { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED, "", "" },
   { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
     switches::kOverscrollHistoryNavigation,
     "0" },
   { IDS_OVERSCROLL_HISTORY_NAVIGATION_SIMPLE_UI,
     switches::kOverscrollHistoryNavigation,
     "2" }
 };
 #endif
 
+const Experiment::Choice kTouchTextSelectionStrategyChoices[] = {
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
+  { IDS_TOUCH_SELECTION_STRATEGY_CHARACTER,
+    switches::kTouchTextSelectionStrategy,

[jdduke (slow), 2015/04/21 14:45:08]

I can't say I love the use of ordinals to describe the strategy. People wanting
to "experiment" will have to look at the soure before they're able to make a
change. Any reason to use integers instead of string constants?

[mfomitchev, 2015/04/21 15:02:37]

These will shown as strings in the about://flags UI: Default, Character, and
Direction (see generated_resources.grd). I suppose I could turn "0" and "1" into
"character" and "direction" as well. I don't have much of an opinion either way
- I just copied kOverscrollHistoryNavigationChoices figuring it's better to be
consistent.

[jdduke (slow), 2015/04/21 15:13:40]

Ah, I didn't realize the names already get pretty printed, definitely fine as-is
for me!

+    "0" },
+  { IDS_TOUCH_SELECTION_STRATEGY_DIRECTION,
+    switches::kTouchTextSelectionStrategy,
+    "1" }
+};
+
 #if !defined(DISABLE_NACL)
 const Experiment::Choice kNaClDebugMaskChoices[] = {
   // Secure shell can be used on ChromeOS for forwarding the TCP port opened by
   // debug stub to a remote machine. Since secure shell uses NaCl, we usually
   // want to avoid debugging that. The PNaCl translator is also a NaCl module,
   // so by default we want to avoid debugging that.
   // NOTE: As the default value must be the empty string, the mask excluding
   // the PNaCl translator and secure shell is substituted elsewhere.
   { IDS_NACL_DEBUG_MASK_CHOICE_EXCLUDE_UTILS_PNACL, "", "" },
   { IDS_NACL_DEBUG_MASK_CHOICE_DEBUG_ALL, switches::kNaClDebugMask, "*://*" },
@@ skipping 1002 matching lines @@
   },
   {
     "enable-touch-editing",
     IDS_FLAGS_ENABLE_TOUCH_EDITING_NAME,
     IDS_FLAGS_ENABLE_TOUCH_EDITING_DESCRIPTION,
     kOsCrOS | kOsWin | kOsLinux,
     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableTouchEditing,
                               switches::kDisableTouchEditing)
   },
   {
+      "touch-selection-strategy",

[jdduke (slow), 2015/04/17 17:05:16]

"touch-selection-strategy" values of 0/1 don't really tell us anything. Can we
just call this |kEnableSmartTextSelection| with an appropriate flag description,
and use that to determine the right strategy/granularity?

[mfomitchev, 2015/04/17 17:14:37]

Eventually I'd like to add another strategy: shrink by character only until the
word boundary and then switch to word granularity if you continue shrinking.
Then we will have three strategies, and enable/disable won't work.

[jdduke (slow), 2015/04/17 19:03:35]

Acknowledged.

+      IDS_FLAGS_TOUCH_SELECTION_STRATEGY_NAME,
+      IDS_FLAGS_TOUCH_SELECTION_STRATEGY_DESCRIPTION,
+      kOsAndroid,   // TODO(mfomitchev): Add CrOS/Win/Linux support soon.
+      MULTI_VALUE_TYPE(kTouchTextSelectionStrategyChoices)
+  },
+  {
     "enable-stale-while-revalidate",
     IDS_FLAGS_ENABLE_STALE_WHILE_REVALIDATE_NAME,
     IDS_FLAGS_ENABLE_STALE_WHILE_REVALIDATE_DESCRIPTION,
     kOsAll,
     SINGLE_VALUE_TYPE(switches::kEnableStaleWhileRevalidate)
   },
   {
     "enable-suggestions-service",
     IDS_FLAGS_ENABLE_SUGGESTIONS_SERVICE_NAME,
     IDS_FLAGS_ENABLE_SUGGESTIONS_SERVICE_DESCRIPTION,
@@ skipping 1720 matching lines @@
 }
 
 const Experiment* GetExperiments(size_t* count) {
   *count = num_experiments;
   return experiments;
 }
 
 }  // namespace testing
 
 }  // namespace about_flags