first crack at writing a linter for .ui files

Change-Id: I51fd2b426e3292647ca618bf867d22275d7ed4fd
Reviewed-on: https://gerrit.libreoffice.org/2762Tested-by: Caolán McNamara <caolanm@redhat.com>
Reviewed-by: Caolán McNamara <caolanm@redhat.com>

bin/lint-ui.py

+#!/usr/bin/env python3
+#
+# This file is part of the LibreOffice project.
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, you can obtain one at http://mozilla.org/MPL/2.0/.
+#
+# Takes a LibreOffice .ui file and provides linting tips for maintaining
+# a consistent look for dialogs
+
+import sys
+import xml.etree.ElementTree as ET
+
+DEFAULT_WARNING_STR = 'Lint assertion failed'
+
+POSSIBLE_TOP_LEVEL_WIDGETS = ['GtkDialog', 'GtkBox', 'GtkFrame', 'GtkGrid']
+IGNORED_TOP_LEVEL_WIDGETS = ['GtkAdjustment', 'GtkImage', 'GtkListStore', 'GtkSizeGroup', 'GtkMenu', 'GtkTextBuffer']
+BORDER_WIDTH = '6'
+BUTTON_BOX_SPACING = '12'
+ALIGNMENT_TOP_PADDING = '6'
+
+def lint_assert(predicate, warning=DEFAULT_WARNING_STR):
+    if not predicate:
+        print("    * " + warning)
+
+def check_top_level_widget(element):
+    # check widget type
+    widget_type = element.attrib['class']
+    lint_assert(widget_type in POSSIBLE_TOP_LEVEL_WIDGETS,
+                "Top level widget should be 'GtkDialog', 'GtkFrame', 'GtkBox', or 'GtkGrid'")
+
+    # check border_width property
+    border_width_properties = element.findall("property[@name='border_width']")
+    if len(border_width_properties) < 1:
+        lint_assert(False, "No border_width set on top level widget. Should probably be " + BORDER_WIDTH)
+    if len(border_width_properties) == 1:
+        border_width = border_width_properties[0]
+        lint_assert(border_width.text == BORDER_WIDTH,
+                    "Top level 'border_width' property should be " + BORDER_WIDTH)
+
+def check_button_box_spacing(element):
+    spacing = element.findall("property[@name='spacing']")[0]
+    lint_assert(spacing.text == BUTTON_BOX_SPACING,
+                "Button box 'spacing' should be " + BUTTON_BOX_SPACING)
+
+def check_frames(root):
+    frames = [element for element in root.findall('.//object') if element.attrib['class'] == 'GtkFrame']
+    for frame in frames:
+        frame_alignments = frame.findall("./child/object[@class='GtkAlignment']")
+        assert len(frame_alignments) <= 1
+        if len(frame_alignments) < 1:
+            lint_assert(False, "No GtkAlignment in GtkFrame with id = '" + frame.attrib['id'] + "'")
+        if len(frame_alignments) == 1:
+            alignment = frame_alignments[0]
+            check_alignment_top_padding(alignment)
+
+def check_alignment_top_padding(alignment):
+    top_padding_properties = alignment.findall("./property[@name='top_padding']")
+    assert len(top_padding_properties) <= 1
+    if len(top_padding_properties) < 1:
+        lint_assert(False, "No GtkAlignment 'top_padding' set. Should probably be " + ALIGNMENT_TOP_PADDING)
+    if len(top_padding_properties) == 1:
+        top_padding = top_padding_properties[0]
+        lint_assert(top_padding.text == ALIGNMENT_TOP_PADDING,
+                    "GtkAlignment 'top_padding' should be " + ALIGNMENT_TOP_PADDING)
+
+def main():
+    print(" == " + sys.argv[1] + " ==")
+    tree = ET.parse(sys.argv[1])
+    root = tree.getroot()
+
+    top_level_widgets = [element for element in root.findall('object') if element.attrib['class'] not in IGNORED_TOP_LEVEL_WIDGETS]
+    assert len(top_level_widgets) == 1
+
+    top_level_widget = top_level_widgets[0]
+    check_top_level_widget(top_level_widget)
+
+    # TODO - only do this if we have a GtkDialog?
+    # check button box spacing
+    button_box = top_level_widget.findall("child[@id='dialog-vbox1']")
+    if len(button_box) > 0:
+        element = button_box[0]
+        check_button_box_spacing(element)
+
+    check_frames(root)
+
+if __name__ == "__main__":
+    main()