flutter_runner::FocusDelegate Class Reference

#include <focus_delegate.h>

Public Member Functions
	FocusDelegate (fuchsia::ui::views::ViewRefFocusedHandle view_ref_focused, fuchsia::ui::views::FocuserHandle focuser)
void	WatchLoop (std::function< void(bool)> callback)
bool	HandlePlatformMessage (rapidjson::Value request, fml::RefPtr< flutter::PlatformMessageResponse > response)
void	OnChildViewViewRef (uint64_t view_id, fuchsia::ui::views::ViewRef view_ref)
void	OnDisposeChildView (uint64_t view_id)

Detailed Description

Definition at line 18 of file focus_delegate.h.

Constructor & Destructor Documentation

FocusDelegate()

flutter_runner::FocusDelegate::FocusDelegate ( fuchsia::ui::views::ViewRefFocusedHandle  view_ref_focused, fuchsia::ui::views::FocuserHandle  focuser  )

inline

Definition at line 20 of file focus_delegate.h.

      : view_ref_focused_(view_ref_focused.Bind()), focuser_(focuser.Bind()) {}

Member Function Documentation

HandlePlatformMessage()

bool flutter_runner::FocusDelegate::HandlePlatformMessage	(	rapidjson::Value	request,
		fml::RefPtr< flutter::PlatformMessageResponse >	response
	)

Handles the following focus-related platform message requests: View.focus.getCurrent

• Completes with the FocusDelegate's most recent focus state, either [true] or [false]. View.focus.getNext
• Completes with the FocusDelegate's next focus state, either [true] or [false].
• Only one outstanding request may exist at a time. Any others will be completed with [null]. View.focus.request
• Attempts to give focus for a given viewRef. Completes with [0] on success, or [fuchsia::ui::views::Error] on failure.

Returns false if a malformed/invalid request needs to be completed empty.

Definition at line 27 of file focus_delegate.cc.

                                                        {
  auto method = request.FindMember("method");
  if (method == request.MemberEnd() || !method->value.IsString()) {
    return false;
  }
 
  if (method->value == "View.focus.getCurrent") {
    Complete(std::move(response), is_focused_ ? "[true]" : "[false]");
  } else if (method->value == "View.focus.getNext") {
    if (next_focus_request_) {
      FML_LOG(ERROR) << "An outstanding PlatformMessageResponse already exists "
                        "for the next focus state!";
      Complete(std::move(response), "[null]");
    } else {
      next_focus_request_ = std::move(response);
    }
  } else if (method->value == "View.focus.request") {
    auto args_it = request.FindMember("args");
    if (args_it == request.MemberEnd() || !args_it->value.IsObject()) {
      FML_LOG(ERROR) << "No arguments found.";
      return false;
    }
    const auto& args = args_it->value;
 
    auto view_ref = args.FindMember("viewRef");
    if (!view_ref->value.IsUint64()) {
      FML_LOG(ERROR) << "Argument 'viewRef' is not a uint64";
      return false;
    }
 
    zx_handle_t handle = view_ref->value.GetUint64();
    zx_handle_t out_handle;
    zx_status_t status =
        zx_handle_duplicate(handle, ZX_RIGHT_SAME_RIGHTS, &out_handle);
    if (status != ZX_OK) {
      FML_LOG(ERROR) << "Argument 'viewRef' is not valid";
      return false;
    }
    auto ref = fuchsia::ui::views::ViewRef({
        .reference = zx::eventpair(out_handle),
    });
    return RequestFocusByViewRef(std::move(ref), std::move(response));
 
  } else if (method->value == "View.focus.requestById") {
    auto args_it = request.FindMember("args");
    if (args_it == request.MemberEnd() || !args_it->value.IsObject()) {
      FML_LOG(ERROR) << "No arguments found.";
      return false;
    }
    const auto& args = args_it->value;
 
    auto view_id = args.FindMember("viewId");
    if (!view_id->value.IsUint64()) {
      FML_LOG(ERROR) << "Argument 'viewId' is not a uint64";
      return false;
    }
 
    auto id = view_id->value.GetUint64();
    if (child_view_view_refs_.count(id) != 1) {
      FML_LOG(ERROR) << "Argument 'viewId' (" << id
                     << ") does not refer to a valid ChildView";
      Complete(std::move(response), "[1]");
      return true;
    }
 
    return RequestFocusById(id, std::move(response));
  } else {
    return false;
  }
  // All of our methods complete the platform message response.
  return true;
}

OnChildViewViewRef()

void flutter_runner::FocusDelegate::OnChildViewViewRef	(	uint64_t	view_id,
		fuchsia::ui::views::ViewRef	view_ref
	)

Definition at line 102 of file focus_delegate.cc.

                                                                       {
  FML_CHECK(child_view_view_refs_.count(view_id) == 0);
  child_view_view_refs_[view_id] = std::move(view_ref);
}

OnDisposeChildView()

void flutter_runner::FocusDelegate::OnDisposeChildView

(

uint64_t

view_id

)

Definition at line 108 of file focus_delegate.cc.

                                                       {
  FML_CHECK(child_view_view_refs_.count(view_id) == 1);
  child_view_view_refs_.erase(view_id);
}

WatchLoop()

void flutter_runner::FocusDelegate::WatchLoop

(

std::function< void(bool)>

callback

)

Continuously watches the host viewRef for focus events, invoking a callback each time.

The callback is invoked on each Watch() call, which consumes the callback argument. Hence, the callback argument must be copyable, so that a copy can be freely moved into the Watch() call.

This method can only be called once.

Definition at line 11 of file focus_delegate.cc.

                                                              {
  if (watch_loop_) {
    FML_LOG(ERROR) << "FocusDelegate::WatchLoop() must be called once.";
    return;
  }
 
  watch_loop_ = [this, /*copy*/ callback](auto focus_state) {
    callback(is_focused_ = focus_state.focused());
    Complete(std::exchange(next_focus_request_, nullptr),
             is_focused_ ? "[true]" : "[false]");
    view_ref_focused_->Watch(/*copy*/ watch_loop_);
  };
 
  view_ref_focused_->Watch(/*copy*/ watch_loop_);
}

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The documentation for this class was generated from the following files:

• shell/platform/fuchsia/flutter/focus_delegate.h
• shell/platform/fuchsia/flutter/focus_delegate.cc