Move text_elider to gfx.

R=sky@chromium.org
http://crbug.com/103304

Review URL: https://codereview.chromium.org/23731010

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@222106 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 232 insertions, 0 deletions

diff --git a/ui/gfx/text_elider.h b/ui/gfx/text_elider.h
new file mode 100644
index 0000000..008a1cd
--- /dev/null
+++ b/ui/gfx/text_elider.h
@@ -0,0 +1,232 @@
+// 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.
+//
+// This file defines utility functions for eliding and formatting UI text.
+
+#ifndef UI_GFX_TEXT_ELIDER_H_
+#define UI_GFX_TEXT_ELIDER_H_
+
+#include <string>
+#include <vector>
+
+#include "base/basictypes.h"
+#include "base/strings/string16.h"
+#include "third_party/icu/source/common/unicode/uchar.h"
+#include "third_party/icu/source/i18n/unicode/coll.h"
+#include "ui/gfx/gfx_export.h"
+
+class GURL;
+
+namespace base {
+class FilePath;
+}
+
+namespace gfx {
+class Font;
+class FontList;
+
+UI_EXPORT extern const char kEllipsis[];
+UI_EXPORT extern const char16 kEllipsisUTF16[];
+
+// Elides a well-formed email address (e.g. username@domain.com) to fit into
+// |available_pixel_width| using the specified |font_list|.
+// This function guarantees that the string returned will contain at least one
+// character, other than the ellipses, on either side of the '@'. If it is
+// impossible to achieve these requirements: only an ellipsis will be returned.
+// If possible: this elides only the username portion of the |email|. Otherwise,
+// the domain is elided in the middle so that it splits the available width
+// equally with the elided username (should the username be short enough that it
+// doesn't need half the available width: the elided domain will occupy that
+// extra width).
+UI_EXPORT string16 ElideEmail(const string16& email,
+                              const gfx::FontList& font_list,
+                              int available_pixel_width);
+// Obsolete version.  Use the above version which takes gfx::FontList.
+UI_EXPORT string16 ElideEmail(const string16& email,
+                              const gfx::Font& font,
+                              int available_pixel_width);
+
+// This function takes a GURL object and elides it. It returns a string
+// which composed of parts from subdomain, domain, path, filename and query.
+// A "..." is added automatically at the end if the elided string is bigger
+// than the |available_pixel_width|. For |available_pixel_width| == 0, a
+// formatted, but un-elided, string is returned. |languages| is a comma
+// separated list of ISO 639 language codes and is used to determine what
+// characters are understood by a user. It should come from
+// |prefs::kAcceptLanguages|.
+//
+// Note: in RTL locales, if the URL returned by this function is going to be
+// displayed in the UI, then it is likely that the string needs to be marked
+// as an LTR string (using base::i18n::WrapStringWithLTRFormatting()) so that it
+// is displayed properly in an RTL context. Please refer to
+// http://crbug.com/6487 for more information.
+UI_EXPORT string16 ElideUrl(const GURL& url,
+                            const gfx::FontList& font_list,
+                            int available_pixel_width,
+                            const std::string& languages);
+// Obsolete version.  Use the above version which takes gfx::FontList.
+UI_EXPORT string16 ElideUrl(const GURL& url,
+                            const gfx::Font& font,
+                            int available_pixel_width,
+                            const std::string& languages);
+
+enum ElideBehavior {
+  // Add ellipsis at the end of the string.
+  ELIDE_AT_END,
+  // Add ellipsis in the middle of the string.
+  ELIDE_IN_MIDDLE,
+  // Truncate the end of the string.
+  TRUNCATE_AT_END
+};
+
+// Elides |text| to fit in |available_pixel_width| according to the specified
+// |elide_behavior|.
+UI_EXPORT string16 ElideText(const string16& text,
+                             const gfx::FontList& font_list,
+                             int available_pixel_width,
+                             ElideBehavior elide_behavior);
+// Obsolete version.  Use the above version which takes gfx::FontList.
+UI_EXPORT string16 ElideText(const string16& text,
+                             const gfx::Font& font,
+                             int available_pixel_width,
+                             ElideBehavior elide_behavior);
+
+// Elide a filename to fit a given pixel width, with an emphasis on not hiding
+// the extension unless we have to. If filename contains a path, the path will
+// be removed if filename doesn't fit into available_pixel_width. The elided
+// filename is forced to have LTR directionality, which means that in RTL UI
+// the elided filename is wrapped with LRE (Left-To-Right Embedding) mark and
+// PDF (Pop Directional Formatting) mark.
+UI_EXPORT string16 ElideFilename(const base::FilePath& filename,
+                                 const gfx::FontList& font_list,
+                                 int available_pixel_width);
+// Obsolete version.  Use the above version which takes gfx::FontList.
+UI_EXPORT string16 ElideFilename(const base::FilePath& filename,
+                                 const gfx::Font& font,
+                                 int available_pixel_width);
+
+// SortedDisplayURL maintains a string from a URL suitable for display to the
+// use. SortedDisplayURL also provides a function used for comparing two
+// SortedDisplayURLs for use in visually ordering the SortedDisplayURLs.
+//
+// SortedDisplayURL is relatively cheap and supports value semantics.
+class UI_EXPORT SortedDisplayURL {
+ public:
+  SortedDisplayURL(const GURL& url, const std::string& languages);
+  SortedDisplayURL();
+  ~SortedDisplayURL();
+
+  // Compares this SortedDisplayURL to |url| using |collator|. Returns a value
+  // < 0, = 1 or > 0 as to whether this url is less then, equal to or greater
+  // than the supplied url.
+  int Compare(const SortedDisplayURL& other, icu::Collator* collator) const;
+
+  // Returns the display string for the URL.
+  const string16& display_url() const { return display_url_; }
+
+ private:
+  // Returns everything after the host. This is used by Compare if the hosts
+  // match.
+  string16 AfterHost() const;
+
+  // Host name minus 'www.'. Used by Compare.
+  string16 sort_host_;
+
+  // End of the prefix (spec and separator) in display_url_.
+  size_t prefix_end_;
+
+  string16 display_url_;
+
+  DISALLOW_COPY_AND_ASSIGN(SortedDisplayURL);
+};
+
+// Functions to elide strings when the font information is unknown.  As
+// opposed to the above functions, the ElideString() and
+// ElideRectangleString() functions operate in terms of character units,
+// not pixels.
+
+// If the size of |input| is more than |max_len|, this function returns
+// true and |input| is shortened into |output| by removing chars in the
+// middle (they are replaced with up to 3 dots, as size permits).
+// Ex: ElideString(ASCIIToUTF16("Hello"), 10, &str) puts Hello in str and
+// returns false.  ElideString(ASCIIToUTF16("Hello my name is Tom"), 10, &str)
+// puts "Hell...Tom" in str and returns true.
+// TODO(tsepez): Doesn't handle UTF-16 surrogate pairs properly.
+// TODO(tsepez): Doesn't handle bidi properly.
+UI_EXPORT bool ElideString(const string16& input, int max_len,
+                           string16* output);
+
+// Reformat |input| into |output| so that it fits into a |max_rows| by
+// |max_cols| rectangle of characters.  Input newlines are respected, but
+// lines that are too long are broken into pieces.  If |strict| is true,
+// we break first at naturally occuring whitespace boundaries, otherwise
+// we assume some other mechanism will do this in approximately the same
+// spot after the fact.  If the word itself is too long, we always break
+// intra-word (respecting UTF-16 surrogate pairs) as necssary. Truncation
+// (indicated by an added 3 dots) occurs if the result is still too long.
+//  Returns true if the input had to be truncated (and not just reformatted).
+UI_EXPORT bool ElideRectangleString(const string16& input, size_t max_rows,
+                                    size_t max_cols, bool strict,
+                                    string16* output);
+
+// Specifies the word wrapping behavior of |ElideRectangleText()| when a word
+// would exceed the available width.
+enum WordWrapBehavior {
+  // Words that are too wide will be put on a new line, but will not be
+  // truncated or elided.
+  IGNORE_LONG_WORDS,
+
+  // Words that are too wide will be put on a new line and will be truncated to
+  // the available width.
+  TRUNCATE_LONG_WORDS,
+
+  // Words that are too wide will be put on a new line and will be elided to the
+  // available width.
+  ELIDE_LONG_WORDS,
+
+  // Words that are too wide will be put on a new line and will be wrapped over
+  // multiple lines.
+  WRAP_LONG_WORDS,
+};
+
+// Indicates whether the |available_pixel_width| by |available_pixel_height|
+// rectangle passed to |ElideRectangleText()| had insufficient space to
+// accommodate the given |text|, leading to elision or truncation.
+enum ReformattingResultFlags {
+  INSUFFICIENT_SPACE_HORIZONTAL = 1 << 0,
+  INSUFFICIENT_SPACE_VERTICAL = 1 << 1,
+};
+
+// Reformats |text| into output vector |lines| so that the resulting text fits
+// into an |available_pixel_width| by |available_pixel_height| rectangle with
+// the specified |font_list|. Input newlines are respected, but lines that are
+// too long are broken into pieces. For words that are too wide to fit on a
+// single line, the wrapping behavior can be specified with the |wrap_behavior|
+// param. Returns a combination of |ReformattingResultFlags| that indicate
+// whether the given rectangle had insufficient space to accommodate |texŧ|,
+// leading to elision or truncation (and not just reformatting).
+UI_EXPORT int ElideRectangleText(const string16& text,
+                                 const gfx::FontList& font_list,
+                                 int available_pixel_width,
+                                 int available_pixel_height,
+                                 WordWrapBehavior wrap_behavior,
+                                 std::vector<string16>* lines);
+// Obsolete version.  Use the above version which takes gfx::FontList.
+UI_EXPORT int ElideRectangleText(const string16& text,
+                                 const gfx::Font& font,
+                                 int available_pixel_width,
+                                 int available_pixel_height,
+                                 WordWrapBehavior wrap_behavior,
+                                 std::vector<string16>* lines);
+
+// Truncates the string to length characters. This breaks the string at
+// the first word break before length, adding the horizontal ellipsis
+// character (unicode character 0x2026) to render ...
+// The supplied string is returned if the string has length characters or
+// less.
+UI_EXPORT string16 TruncateString(const string16& string, size_t length);
+
+}  // namespace gfx
+
+#endif  // UI_GFX_TEXT_ELIDER_H_