[orca] Add support for structural navigation by image

[Joanmarie Diggs <joanied src gnome org>]

commit 4841c1949787d4d2664591bddd1539bcbc9c6a12
Author: Joanmarie Diggs <jdiggs igalia com>
Date:   Sat Aug 16 11:11:31 2014 -0400

    Add support for structural navigation by image

 src/orca/cmdnames.py                      |    9 +++
 src/orca/guilabels.py                     |   11 ++++
 src/orca/messages.py                      |    5 ++
 src/orca/scripts/toolkits/Gecko/script.py |    1 +
 src/orca/structural_navigation.py         |   84 +++++++++++++++++++++++++++++
 5 files changed, 110 insertions(+), 0 deletions(-)
---
diff --git a/src/orca/cmdnames.py b/src/orca/cmdnames.py
index 2b71686..b30a333 100644
--- a/src/orca/cmdnames.py
+++ b/src/orca/cmdnames.py
@@ -823,6 +823,15 @@ HEADING_AT_LEVEL_NEXT = _("Goes to next heading at level %d.")
 # <h1> is a heading at level 1, <h2> is a heading at level 2, etc.
 HEADING_AT_LEVEL_LIST = _("Displays a list of headings at level %d.")
 
+# Translators: this is for navigating among images in a document.
+IMAGE_PREV = _("Goes to previous image.")
+
+# Translators: this is for navigating among images in a document.
+IMAGE_NEXT = _("Goes to next image.")
+
+# Translators: this is for navigating among images in a document.
+IMAGE_LIST = _("Displays a list of images.")
+
 # Translators: this is for navigating among ARIA landmarks in a document. ARIA
 # role landmarks are the W3C defined HTML tag attribute 'role' used to identify
 # important part of webpage like banners, main context, search etc.
diff --git a/src/orca/guilabels.py b/src/orca/guilabels.py
index ba7674d..5d12c82 100644
--- a/src/orca/guilabels.py
+++ b/src/orca/guilabels.py
@@ -396,6 +396,12 @@ SN_HEADER_HEADING = C_("structural navigation", "Heading")
 # Translators: Orca has a command that presents a list of structural navigation
 # objects in a dialog box so that users can navigate more quickly than they
 # could with native keyboard navigation. This is the title for a column which
+# contains the text (alt text, title, etc.) associated with an image.
+SN_HEADER_IMAGE = C_("structural navigation", "Image")
+
+# Translators: Orca has a command that presents a list of structural navigation
+# objects in a dialog box so that users can navigate more quickly than they
+# could with native keyboard navigation. This is the title for a column which
 # contains the label of a form field.
 SN_HEADER_LABEL = C_("structural navigation", "Label")
 
@@ -532,6 +538,11 @@ SN_TITLE_HEADING = C_("structural navigation", "Headings")
 # Translators: Orca has a command that presents a list of structural navigation
 # objects in a dialog box so that users can navigate more quickly than they
 # could with native keyboard navigation. This is the title of such a dialog box.
+SN_TITLE_IMAGE = C_("structural navigation", "Images")
+
+# Translators: Orca has a command that presents a list of structural navigation
+# objects in a dialog box so that users can navigate more quickly than they
+# could with native keyboard navigation. This is the title of such a dialog box.
 # Level will be a "1" for <h1>, a "2" for <h2>, and so on.
 SN_TITLE_HEADING_AT_LEVEL = C_("structural navigation", "Headings at Level %d")
 
diff --git a/src/orca/messages.py b/src/orca/messages.py
index 1fc1bc7..ffc550e 100644
--- a/src/orca/messages.py
+++ b/src/orca/messages.py
@@ -1199,6 +1199,11 @@ NO_MORE_HEADINGS = _("No more headings.")
 # at the desired level can be found.
 NO_MORE_HEADINGS_AT_LEVEL = _("No more headings at level %d.")
 
+# Translators: This is for navigating document content by moving from image
+# to image. This is a detailed message which will be presented to the user
+# if no more images can be found.
+NO_MORE_IMAGES = _("No more images.")
+
 # Translators: this is for navigating to the previous ARIA role landmark.
 # ARIA role landmarks are the W3C defined HTML tag attribute 'role' used to
 # identify important part of webpage like banners, main context, search etc.
diff --git a/src/orca/scripts/toolkits/Gecko/script.py b/src/orca/scripts/toolkits/Gecko/script.py
index 1fc41fd..3111e97 100644
--- a/src/orca/scripts/toolkits/Gecko/script.py
+++ b/src/orca/scripts/toolkits/Gecko/script.py
@@ -291,6 +291,7 @@ class Script(default.Script):
                         GeckoStructuralNavigation.ENTRY,
                         GeckoStructuralNavigation.FORM_FIELD,
                         GeckoStructuralNavigation.HEADING,
+                        GeckoStructuralNavigation.IMAGE,
                         GeckoStructuralNavigation.LANDMARK,
                         GeckoStructuralNavigation.LINK,
                         GeckoStructuralNavigation.LIST,
diff --git a/src/orca/structural_navigation.py b/src/orca/structural_navigation.py
index f0a34d6..230eac0 100644
--- a/src/orca/structural_navigation.py
+++ b/src/orca/structural_navigation.py
@@ -532,6 +532,7 @@ class StructuralNavigation:
     ENTRY           = "entry"
     FORM_FIELD      = "formField"
     HEADING         = "heading"
+    IMAGE           = "image"
     LANDMARK        = "landmark"
     LINK            = "link"
     LIST            = "list"        # Bulleted/numbered lists
@@ -574,6 +575,9 @@ class StructuralNavigation:
                     pyatspi.ROLE_DOCUMENT_FRAME,
                     pyatspi.ROLE_DOCUMENT_WEB]
 
+    IMAGE_ROLES = [pyatspi.ROLE_IMAGE,
+                   pyatspi.ROLE_IMAGE_MAP]
+
     def __init__(self, script, enabledTypes, enabled=False):
         """Creates an instance of the StructuralNavigation class.
 
@@ -1699,6 +1703,15 @@ class StructuralNavigation:
             item = self._getSelectedItem(obj)
             if item:
                 text = item.name
+        if not text and obj.getRole() == pyatspi.ROLE_IMAGE:
+            try:
+                image = obj.queryImage()
+            except:
+                text = obj.description
+            else:
+                text = image.imageDescription or obj.description
+            if not text and obj.parent.getRole() == pyatspi.ROLE_LINK:
+                text = self._script.utilities.linkBasename(obj.parent)
 
         return text
 
@@ -2525,6 +2538,77 @@ class StructuralNavigation:
 
     ########################
     #                      #
+    # Images               #
+    #                      #
+    ########################
+
+    def _imageBindings(self):
+        """Returns a dictionary of [keysymstring, modifiers, description]
+        lists for navigating amongst images."""
+
+        bindings = {}
+        prevDesc = cmdnames.IMAGE_PREV
+        bindings["previous"] = ["g", keybindings.SHIFT_MODIFIER_MASK, prevDesc]
+
+        nextDesc = cmdnames.IMAGE_NEXT
+        bindings["next"] = ["g", keybindings.NO_MODIFIER_MASK, nextDesc]
+
+        listDesc = cmdnames.IMAGE_LIST
+        bindings["list"] = ["g", keybindings.SHIFT_ALT_MODIFIER_MASK, listDesc]
+        return bindings
+
+    def _imageCriteria(self, collection, arg=None):
+        """Returns the MatchCriteria to be used for locating images
+        by collection.
+
+        Arguments:
+        - collection: the collection interface for the document
+        - arg: an optional argument which may need to be included in
+          the criteria (e.g. the level of a heading).
+        """
+
+        return MatchCriteria(collection, roles=self.IMAGE_ROLES)
+
+    def _imagePredicate(self, obj, arg=None):
+        """The predicate to be used for verifying that the object
+        obj is an image.
+
+        Arguments:
+        - obj: the accessible object under consideration.
+        - arg: an optional argument which may need to be included in
+          the criteria (e.g. the level of a heading).
+        """
+
+        return (obj and obj.getRole() in self.IMAGE_ROLES)
+
+    def _imagePresentation(self, obj, arg=None):
+        """Presents the image/graphic or indicates that one was not found.
+
+        Arguments:
+        - obj: the accessible object under consideration.
+        - arg: an optional argument which may need to be included in
+          the criteria (e.g. the level of a heading).
+        """
+
+        if obj:
+            [newObj, characterOffset] = self._getCaretPosition(obj)
+            self._setCaretPosition(newObj, characterOffset)
+            self._presentObject(obj, 0)
+        else:
+            full = messages.NO_MORE_IMAGES
+            brief = messages.STRUCTURAL_NAVIGATION_NOT_FOUND
+            self._script.presentMessage(full, brief)
+
+    def _imageDialogData(self):
+        columnHeaders = [guilabels.SN_HEADER_IMAGE]
+
+        def rowData(obj):
+            return [self._getText(obj) or self._getRoleName(obj)]
+
+        return guilabels.SN_TITLE_IMAGE, columnHeaders, rowData
+
+    ########################
+    #                      #
     # Landmarks            #
     #                      #
     ########################