1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #ifndef UI_BASE_X_SELECTION_REQUESTOR_H_
6 #define UI_BASE_X_SELECTION_REQUESTOR_H_
10 // Get rid of a macro from Xlib.h that conflicts with Aura's RootWindow class.
16 #include "base/basictypes.h"
17 #include "base/callback.h"
18 #include "base/memory/ref_counted_memory.h"
19 #include "ui/base/ui_base_export.h"
20 #include "ui/gfx/x/x11_atom_cache.h"
23 class PlatformEventDispatcher;
26 // Requests and later receives data from the X11 server through the selection
29 // X11 uses a system called "selections" to implement clipboards and drag and
30 // drop. This class interprets messages from the statefull selection request
31 // API. SelectionRequestor should only deal with the X11 details; it does not
32 // implement per-component fast-paths.
33 class UI_BASE_EXPORT SelectionRequestor {
35 SelectionRequestor(Display* xdisplay,
37 ::Atom selection_name,
38 PlatformEventDispatcher* dispatcher);
39 ~SelectionRequestor();
41 // Does the work of requesting |target| from the selection we handle,
42 // spinning up the nested message loop, and reading the resulting data
43 // back. |out_data| is allocated with the X allocator and must be freed with
44 // XFree(). |out_data_bytes| is the length in machine chars, while
45 // |out_data_items| is the length in |out_type| items.
46 bool PerformBlockingConvertSelection(
48 scoped_refptr<base::RefCountedMemory>* out_data,
49 size_t* out_data_bytes,
50 size_t* out_data_items,
53 // Requests |target| from the selection that we handle, passing |parameter|
54 // as a parameter to XConvertSelection().
55 void PerformBlockingConvertSelectionWithParameter(
57 const std::vector< ::Atom>& parameter);
59 // Returns the first of |types| offered by the current selection holder, or
60 // returns NULL if none of those types are available.
61 SelectionData RequestAndWaitForTypes(const std::vector< ::Atom>& types);
63 // It is our owner's responsibility to plumb X11 SelectionNotify events on
65 void OnSelectionNotify(const XSelectionEvent& event);
68 // A request that has been issued and we are waiting for a response to.
69 struct PendingRequest {
70 explicit PendingRequest(Atom target);
73 // Data to the current XConvertSelection request. Used for error detection;
74 // we verify it on the return message.
77 // Called to terminate the nested message loop.
78 base::Closure quit_closure;
80 // The property in the returning SelectNotify message is used to signal
81 // success. If None, our request failed somehow. If equal to the property
82 // atom that we sent in the XConvertSelection call, we can read that
83 // property on |x_window_| for the requested data.
84 ::Atom returned_property;
86 // Set to true when return_property is populated.
90 // Blocks till SelectionNotify is received for the target specified in
92 void BlockTillSelectionNotifyForRequest(PendingRequest* request);
98 // The X11 selection that this instance communicates on.
99 ::Atom selection_name_;
101 // Dispatcher which handles SelectionNotify and SelectionRequest for
102 // |selection_name_|. PerformBlockingConvertSelection() calls the
103 // dispatcher directly if PerformBlockingConvertSelection() is called after
104 // the PlatformEventSource is destroyed.
106 PlatformEventDispatcher* dispatcher_;
108 // A list of requests for which we are waiting for responses.
109 std::list<PendingRequest*> pending_requests_;
111 X11AtomCache atom_cache_;
113 DISALLOW_COPY_AND_ASSIGN(SelectionRequestor);
118 #endif // UI_BASE_X_SELECTION_REQUESTOR_H_