Support InputMethodManager#updateCursorAnchorInfo for Android 5.0

ui/base/ime/android/cursor_anchor_info_controller.cc

Index: ui/base/ime/android/cursor_anchor_info_controller.cc
diff --git a/ui/base/ime/android/cursor_anchor_info_controller.cc b/ui/base/ime/android/cursor_anchor_info_controller.cc
new file mode 100644
index 0000000000000000000000000000000000000000..ca4488dabace7fad9cab7fe1149ef8b984140718
--- /dev/null
+++ b/ui/base/ime/android/cursor_anchor_info_controller.cc
@@ -0,0 +1,329 @@
+// Copyright (c) 2014 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 "ui/base/ime/android/cursor_anchor_info_controller.h"
+
+#include "base/android/build_info.h"
+#include "base/strings/string_piece.h"
+#include "base/strings/stringprintf.h"
+#include "cc/output/compositor_frame_metadata.h"
+#include "cc/output/viewport_selection_bound.h"
+#include "ui/base/ime/android/cursor_anchor_info_builder.h"
+#include "ui/base/ime/android/cursor_anchor_info_sender.h"
+
+namespace ui {
+namespace {
+
+class CursorAnchorInfoControllerImpl final
+    : public CursorAnchorInfoController {
+ public:
+  CursorAnchorInfoControllerImpl(
+      CursorAnchorInfoSender* sender,
+      scoped_ptr<CursorAnchorInfoBuilder> builder);
+
+  ~CursorAnchorInfoControllerImpl() override;
+
+  void OnFocusedNodeChanged(bool is_editable_node) override;
+
+  void OnTextInputStateChanged(
+      const base::string16& text,
+      const gfx::Range& selection_range,
+      const gfx::Range& composition_range) override;
+
+  void OnCompositionRangeChanged(
+      const gfx::Range& range,
+      const std::vector<gfx::Rect>& character_bounds) override;
+
+  void OnFrameMetadataUpdated(
+      const cc::CompositorFrameMetadata& frame_metadata,
+      const gfx::Vector2d& view_offset) override;
+
+  bool OnRequestCursorUpdates(uint32 cursor_update_mode) override;
+
+ private:
+  void UpdateBuilder();
+  void ScheduleUpdate();
+  bool HasPendingUpdate() const;
+  void ClearPendingUpdate();
+  void SetMonitorMode(bool enabled);
+
+  // Doesn't own.
+  CursorAnchorInfoSender* cursor_anchor_info_sender_;
+  scoped_ptr<CursorAnchorInfoBuilder> cursor_anchor_info_builder_;
+
+  bool editable_;
+
+  base::string16 text_;
+  gfx::Range selection_range_;
+  gfx::Range composition_range_;
+  std::vector<gfx::Rect> character_bounds_;
+  gfx::Range character_bounds_range_;
+  bool has_insertion_marker_;
+  bool is_insertion_marker_visible_;
+  gfx::RectF insertion_marker_rect_;
+  bool has_coordinate_info_;
+  float scale_;
+  gfx::Vector2dF translation_;
+
+  bool has_pending_request_;
+  bool monitor_mode_enabled_;
+
+  DISALLOW_COPY_AND_ASSIGN(CursorAnchorInfoControllerImpl);
+};
+
+CursorAnchorInfoControllerImpl::CursorAnchorInfoControllerImpl(
+    CursorAnchorInfoSender* sender,
+    scoped_ptr<CursorAnchorInfoBuilder> builder)
+    : cursor_anchor_info_sender_(sender),
+      cursor_anchor_info_builder_(builder.Pass()),
+      editable_(false),
+      selection_range_(gfx::Range::InvalidRange()),
+      composition_range_(gfx::Range::InvalidRange()),
+      has_insertion_marker_(false),
+      is_insertion_marker_visible_(false),
+      has_coordinate_info_(false),
+      scale_(1.0f),
+      has_pending_request_(false),
+      monitor_mode_enabled_(false) {
+}
+
+CursorAnchorInfoControllerImpl::~CursorAnchorInfoControllerImpl() {
+}
+
+void CursorAnchorInfoControllerImpl::OnFocusedNodeChanged(
+    bool is_editable_node) {
+  editable_ = is_editable_node;
+  text_.clear();
+  selection_range_ = gfx::Range::InvalidRange();
+  composition_range_ = gfx::Range::InvalidRange();
+  character_bounds_.clear();
+  character_bounds_range_ = gfx::Range::InvalidRange();
+  has_insertion_marker_ = false;
+  is_insertion_marker_visible_= false;
+  insertion_marker_rect_.SetRect(0.0f, 0.0f, 0.0f, 0.0f);
+  has_coordinate_info_ = false;
+  scale_ = 1.0f;
+  translation_ = gfx::Vector2d();
+}
+
+void CursorAnchorInfoControllerImpl::OnTextInputStateChanged(
+    const base::string16& text,
+    const gfx::Range& selection_range,
+    const gfx::Range& composition_range) {
+  if (!editable_)
+    return;
+
+  if (monitor_mode_enabled_) {
+    const bool changed =
+        text_ != text
+        || selection_range_ != selection_range
+        || composition_range_ != composition_range;
+    if (changed)
+      has_pending_request_ = true;
+  }
+
+  text_ = text;
+  selection_range_ = selection_range;
+  composition_range_ = composition_range;
+}
+
+void CursorAnchorInfoControllerImpl::OnCompositionRangeChanged(
+    const gfx::Range& range,
+    const std::vector<gfx::Rect>& character_bounds) {
+  if (!editable_)
+    return;
+
+  if (monitor_mode_enabled_) {
+    const bool changed =
+        character_bounds_ != character_bounds
+        || character_bounds_range_ != range;
+    if (changed)
+      has_pending_request_ = true;
+  }
+
+  character_bounds_ = character_bounds;
+  character_bounds_range_ = range;
+}
+
+void CursorAnchorInfoControllerImpl::OnFrameMetadataUpdated(
+    const cc::CompositorFrameMetadata& frame_metadata,
+    const gfx::Vector2d& view_offset) {
+  if (!editable_)
+    return;
+
+  const auto& selection_start = frame_metadata.selection_start;
+
+  const float scale =
+      frame_metadata.device_scale_factor * frame_metadata.page_scale_factor;
+  const auto translation =
+      gfx::ScaleVector2d(frame_metadata.root_scroll_offset, -scale)

[jdduke (slow), 2015/01/12 16:33:44]

Hmm, it looks like you're trying to synchronize the IME position with the root
scroll offset. What if the editable region is in a scrolling div, i.e., it can
scroll without updating the root scroll offset?

[yukawa, 2015/01/12 17:08:30]

I cannot check it right now as I'm in my home, but I'll make sure to test it
today.  Basically it depends on how ImeCompositionRangeChanged() and
cc::CompositorFrameMetadata::selection_start::{edge_top, edge_bottom} behave
in such a situation.

Anyway your review about coordinate transformation here is really helpful
as I have a little knowledge of Chromium compositor.

+      + gfx::Vector2dF(view_offset.x(), view_offset.y())
+      + frame_metadata.location_bar_offset
+      + frame_metadata.location_bar_content_translation;
+
+  const bool has_insertion_marker =
+      selection_start.type == cc::SELECTION_BOUND_CENTER;
+  const bool is_insertion_marker_visible = selection_start.visible;
+  const gfx::PointF insertion_marker_origin = has_insertion_marker
+      ? selection_start.edge_top
+      : gfx::PointF(0.0f, 0.0f);
+  const float insertion_marker_height = has_insertion_marker
+      ? selection_start.edge_bottom.y() - selection_start.edge_top.y()
+      : 0.0f;
+  const gfx::SizeF insertion_marker_size(0.0f, insertion_marker_height);
+  const gfx::RectF insertion_marker_rect(insertion_marker_origin,
+                                         insertion_marker_size);
+  if (monitor_mode_enabled_) {
+    const bool changed =
+        !has_coordinate_info_
+        || scale_ != scale
+        || translation_ != translation
+        || has_insertion_marker_ != has_insertion_marker
+        || is_insertion_marker_visible_ != is_insertion_marker_visible
+        || insertion_marker_rect_ != insertion_marker_rect;
+    if (changed)
+      has_pending_request_ = true;
+  }
+
+  scale_ = scale;
+  translation_ = translation;
+  has_insertion_marker_ = has_insertion_marker;
+  is_insertion_marker_visible_ = is_insertion_marker_visible;
+  insertion_marker_rect_ = insertion_marker_rect;
+  has_coordinate_info_ = true;
+
+  if (cursor_anchor_info_sender_
+      && cursor_anchor_info_builder_
+      && HasPendingUpdate()) {
+    UpdateBuilder();
+    cursor_anchor_info_sender_->SendCursorAnchorInfo(
+        cursor_anchor_info_builder_.get());
+    ClearPendingUpdate();
+  }
+}
+
+bool CursorAnchorInfoControllerImpl::OnRequestCursorUpdates(
+    uint32 cursor_update_mode) {
+  if (!editable_)
+    return false;
+
+  // Should return false if at least one unknown bit is set, because we don't
+  // know what is requested by such a bit.
+  const static uint32 kKnownFlags =
+      kCursorUpdateModeImmediate | kCursorUpdateModeMonitor;
+  if ((cursor_update_mode & ~kKnownFlags) != 0)
+    return false;
+
+  const bool update_immediate = cursor_update_mode & kCursorUpdateModeImmediate;
+  const bool update_monitor = cursor_update_mode & kCursorUpdateModeMonitor;
+
+  SetMonitorMode(update_monitor);
+  if (update_immediate)
+    ScheduleUpdate();
+
+  if (cursor_anchor_info_sender_
+      && cursor_anchor_info_builder_
+      && HasPendingUpdate()) {
+    UpdateBuilder();
+    cursor_anchor_info_sender_->SendCursorAnchorInfo(
+        cursor_anchor_info_builder_.get());
+    ClearPendingUpdate();
+  }
+
+  return true;
+}
+
+void CursorAnchorInfoControllerImpl::ScheduleUpdate() {
+  has_pending_request_ = true;
+}
+
+bool CursorAnchorInfoControllerImpl::HasPendingUpdate() const {
+  return has_pending_request_ && has_coordinate_info_;
+}
+
+void CursorAnchorInfoControllerImpl::ClearPendingUpdate() {
+  has_pending_request_ = false;
+}
+
+void CursorAnchorInfoControllerImpl::SetMonitorMode(bool enabled) {
+  monitor_mode_enabled_ = enabled;
+}
+
+void CursorAnchorInfoControllerImpl::UpdateBuilder() {
+  DCHECK(HasPendingUpdate());

[jdduke (slow), 2015/01/14 17:17:09]

Is it necessary to blast all values to the builder atomically? That is, could we
instead incrementally update only the components that change?

[yukawa, 2015/01/14 22:21:59]

Basically we can, but one problem is that the result of
Builder#AddCharacterBounds can be reset only by Builder#Reset.  Therefore, if
character bounds is changed, we need to call Builder#Reset, which means that we
need to update all values.  For other components, yes, we can.  I'll do that if
you think it's worth doing.  What do you think?

+
+  cursor_anchor_info_builder_->Reset();
+
+  if (selection_range_.IsValid())
+    cursor_anchor_info_builder_->SetSelectionRange(selection_range_);
+
+  if (composition_range_.IsValid()) {
+    const auto composition_text = base::StringPiece16(text_).substr(
+        composition_range_.start(),
+        composition_range_.length());
+    cursor_anchor_info_builder_->SetComposingText(
+        composition_range_.start(),
+        composition_text);
+  }
+  if (character_bounds_range_.IsValid()) {
+    const int index_offset = character_bounds_range_.start();
+    for (size_t i = 0; i < character_bounds_.size(); ++i) {
+      cursor_anchor_info_builder_->AddCharacterBounds(
+          index_offset + i,
+          character_bounds_[i],
+          CursorAnchorInfoBuilder::kFlagHasVisibleRegion);
+    }
+  }
+
+  if (has_insertion_marker_) {
+    const uint32 flags = is_insertion_marker_visible_
+        ? CursorAnchorInfoBuilder::kFlagHasVisibleRegion
+        : CursorAnchorInfoBuilder::kFlagHasInvisibleRegion;
+    cursor_anchor_info_builder_->SetInsertionMarkerLocation(
+        insertion_marker_rect_.x(),
+        insertion_marker_rect_.y(),
+        insertion_marker_rect_.bottom(),
+        insertion_marker_rect_.bottom(),
+        flags);
+  }
+
+  gfx::Matrix3F matrix = gfx::Matrix3F::Zeros();
+  matrix.set(scale_, 0.0f, translation_.x(),
+             0.0f, scale_, translation_.y(),
+             0.0f, 0.0f, 1.0f);
+  cursor_anchor_info_builder_->SetMatrix(matrix);
+}
+
+}  // namespace
+
+CursorAnchorInfoController::CursorAnchorInfoController() {
+}
+
+CursorAnchorInfoController::~CursorAnchorInfoController() {
+}
+
+// static
+scoped_ptr<CursorAnchorInfoController>
+CursorAnchorInfoController::Create(CursorAnchorInfoSender* sender) {
+  static bool use_cursor_anchor_info =
+      base::android::BuildInfo::GetInstance()->sdk_int() >= 21;
+  if (!use_cursor_anchor_info)
+    return scoped_ptr<ui::CursorAnchorInfoController>(nullptr);
+
+  return scoped_ptr<ui::CursorAnchorInfoController>(
+      new ui::CursorAnchorInfoControllerImpl(
+          sender,
+          CursorAnchorInfoBuilder::Create()));
+}
+
+// static
+scoped_ptr<CursorAnchorInfoController>
+CursorAnchorInfoController::CreateForTest(
+    CursorAnchorInfoSender* sender,
+    scoped_ptr<ui::CursorAnchorInfoBuilder> builder) {
+  return scoped_ptr<CursorAnchorInfoController>(
+      new ui::CursorAnchorInfoControllerImpl(sender, builder.Pass()));
+}
+
+}  // namespace ui