def collapse_all(self):
     """
     Collapses all triggers and makes all blocks with fold level > 0
     invisible.
     """
     self._clear_block_deco()
     block = self.editor.document().firstBlock()
     last = self.editor.document().lastBlock()
     while block.isValid():
         lvl = TextBlockHelper.get_fold_lvl(block)
         trigger = TextBlockHelper.is_fold_trigger(block)
         if trigger:
             if lvl == 0:
                 self._show_previous_blank_lines(block)
             TextBlockHelper.set_fold_trigger_state(block, True)
         block.setVisible(lvl == 0)
         if block == last and block.text().strip() == '':
             block.setVisible(True)
             self._show_previous_blank_lines(block)
         block = block.next()
     self._refresh_editor_and_scrollbars()
     tc = self.editor.textCursor()
     tc.movePosition(tc.Start)
     self.editor.setTextCursor(tc)
     self.collapse_all_triggered.emit()

 def _on_key_pressed(self, event):
     """
     Override key press to select the current scope if the user wants
     to deleted a folded scope (without selecting it).
     """
     delete_request = event.key() in [QtCore.Qt.Key_Backspace,
                                      QtCore.Qt.Key_Delete]
     if event.text() or delete_request:
         cursor = self.editor.textCursor()
         if cursor.hasSelection():
             # change selection to encompass the whole scope.
             positions_to_check = cursor.selectionStart(), cursor.selectionEnd()
         else:
             positions_to_check = (cursor.position(), )
         for pos in positions_to_check:
             block = self.editor.document().findBlock(pos)
             th = TextBlockHelper()
             if th.is_fold_trigger(block) and th.is_collapsed(block):
                 self.toggle_fold_trigger(block)
                 if delete_request and cursor.hasSelection():
                     scope = FoldScope(self.find_parent_scope(block))
                     tc = TextHelper(self.editor).select_lines(*scope.get_range())
                     if tc.selectionStart() > cursor.selectionStart():
                         start = cursor.selectionStart()
                     else:
                         start = tc.selectionStart()
                     if tc.selectionEnd() < cursor.selectionEnd():
                         end = cursor.selectionEnd()
                     else:
                         end = tc.selectionEnd()
                     tc.setPosition(start)
                     tc.setPosition(end, tc.KeepAnchor)
                     self.editor.setTextCursor(tc)

 def _handle_docstrings(self, block, lvl, prev_block):
     if block.docstring:
         is_start = block.text().strip().startswith('"""')
         if is_start:
             TextBlockHelper.get_fold_lvl(prev_block) + 1
         else:
             pblock = block.previous()
             while pblock.isValid() and pblock.text().strip() == '':
                 pblock = pblock.previous()
             is_start = pblock.text().strip().startswith('"""')
             if is_start:
                 return TextBlockHelper.get_fold_lvl(pblock) + 1
             else:
                 return TextBlockHelper.get_fold_lvl(pblock)
     # fix end of docstring
     elif prev_block and prev_block.text().strip().endswith('"""'):
         single_line = self._single_line_docstring.match(
             prev_block.text().strip())
         if single_line:
             TextBlockHelper.set_fold_lvl(prev_block, lvl)
         else:
             TextBlockHelper.set_fold_lvl(
                 prev_block, TextBlockHelper.get_fold_lvl(
                     prev_block.previous()))
     return lvl

 def detect_fold_level(self, prev_block, block):
     if prev_block:
         prev_text = prev_block.text().strip()
     else:
         prev_text = ''
     if '[]' not in prev_text and '{}' not in prev_text:
         if prev_text.endswith(('{', '[')):
             return TextBlockHelper.get_fold_lvl(prev_block) + 1
         if prev_text.replace(',', '').endswith(('}', ']')):
             return TextBlockHelper.get_fold_lvl(prev_block) - 1
     return TextBlockHelper.get_fold_lvl(prev_block)

def test_dynamic_folding_insert_section():
    # test insert section under empty data division
    # data division (which is not a fold trigger initially) block will become a fold trigger
    editor = CobolCodeEdit()
    editor.setPlainText(section_code, '', '')
    th = TextHelper(editor)
    block = editor.document().findBlockByNumber(2)
    assert TextBlockHelper.is_fold_trigger(block) is False
    cursor = th.goto_line(2, column=len('       DATA DIVISION.'))
    cursor.insertText('\n       WORKING-STORAGE SECTION.')
    assert TextBlockHelper.is_fold_trigger(block) is True

 def expand_all(self):
     """
     Expands all fold triggers.
     """
     block = self.editor.document().firstBlock()
     while block.isValid():
         TextBlockHelper.set_fold_trigger_state(block, False)
         block.setVisible(True)
         block = block.next()
     self._clear_block_deco()
     self._refresh_editor_and_scrollbars()
     self.expand_all_triggered.emit()

def test_expand_all(editor):
    panel = get_panel(editor)
    QTest.qWait(1000)
    panel.collapse_all()
    QTest.qWait(1000)
    panel.expand_all()
    block = editor.document().firstBlock()
    while block.blockNumber() < editor.document().blockCount() - 1:
        assert block.isVisible()
        if TextBlockHelper.is_fold_trigger(block):
            assert TextBlockHelper.is_collapsed(block) is False
        block = block.next()

        def convert(name, editor, to_collapse):
            ti = QtWidgets.QTreeWidgetItem()
            ti.setText(0, name.name)
            if isinstance(name.icon, list):
                icon = QtGui.QIcon.fromTheme(
                    name.icon[0], QtGui.QIcon(name.icon[1]))
            else:
                icon = QtGui.QIcon(name.icon)
            ti.setIcon(0, icon)
            name.block = editor.document().findBlockByNumber(name.line)
            ti.setData(0, QtCore.Qt.UserRole, name)
            ti.setToolTip(0, name.description)
            block_data = name.block.userData()
            if block_data is None:
                block_data = TextBlockUserData()
                name.block.setUserData(block_data)
            block_data.tree_item = ti

            if to_collapse is not None and \
                    TextBlockHelper.is_collapsed(name.block):
                to_collapse.append(ti)

            for ch in name.children:
                ti_ch, to_collapse = convert(ch, editor, to_collapse)
                if ti_ch:
                    ti.addChild(ti_ch)
            return ti, to_collapse

def test_collapse_all(editor):
    panel = get_panel(editor)
    QTest.qWait(1000)
    panel.collapse_all()
    QTest.qWait(1000)
    block = editor.document().firstBlock()
    while block.blockNumber() < editor.document().blockCount() - 1:
        blank_line = len(block.text().strip()) == 0
        if TextBlockHelper.get_fold_lvl(block) > 0:
            if not blank_line:
                assert block.isVisible() is False
        else:
            assert block.isVisible() is True
        if TextBlockHelper.is_fold_trigger(block):
            assert TextBlockHelper.is_collapsed(block) is True
        block = block.next()

    def find_parent_scope(block):
        """
        Find parent scope, if the block is not a fold trigger.

        """
        original = block
        if not TextBlockHelper.is_fold_trigger(block):
            # search level of next non blank line
            while block.text().strip() == '' and block.isValid():
                block = block.next()
            ref_lvl = TextBlockHelper.get_fold_lvl(block) - 1
            block = original
            while (block.blockNumber() and
                   (not TextBlockHelper.is_fold_trigger(block) or
                    TextBlockHelper.get_fold_lvl(block) > ref_lvl)):
                block = block.previous()
        return block

def test_fold_limit(editor):
    editor.syntax_highlighter.fold_detector.limit = 1
    editor.file.open('test/test_api/folding_cases/foo.py')
    block = editor.document().firstBlock()
    while block.blockNumber() < editor.blockCount() - 1:
        assert TextBlockHelper.get_fold_lvl(block) <= 1
        block = block.next()
    editor.syntax_highlighter.fold_detector.limit = sys.maxsize

 def _on_item_state_changed(self, item):
     if self._updating:
         return
     block = item.data(0, QtCore.Qt.UserRole).block
     assert isinstance(item, QtWidgets.QTreeWidgetItem)
     item_state = not item.isExpanded()
     block_state = TextBlockHelper.get_fold_trigger_state(block)
     if item_state != block_state:
         self._updating = True
         self._folding_panel.toggle_fold_trigger(block)
         self._updating = False

 def paintEvent(self, event):
     # Paints the fold indicators and the possible fold region background
     # on the folding panel.
     super(FoldingPanel, self).paintEvent(event)
     painter = QtGui.QPainter(self)
     # Draw background over the selected non collapsed fold region
     if self._mouse_over_line is not None:
         block = self.editor.document().findBlockByNumber(
             self._mouse_over_line)
         try:
             self._draw_fold_region_background(block, painter)
         except ValueError:
             pass
     # Draw fold triggers
     for top_position, line_number, block in self.editor.visible_blocks:
         if TextBlockHelper.is_fold_trigger(block):
             collapsed = TextBlockHelper.get_fold_trigger_state(block)
             mouse_over = self._mouse_over_line == line_number
             self._draw_fold_indicator(
                 top_position, mouse_over, collapsed, painter)
             if collapsed:
                 # check if the block already has a decoration, it might
                 # have been folded by the parent editor/document in the
                 # case of cloned editor
                 for deco in self._block_decos:
                     if deco.block == block:
                         # no need to add a deco, just go to the next block
                         break
                 else:
                     self._add_fold_decoration(block, FoldScope(block))
             else:
                 for deco in self._block_decos:
                     # check if the block decoration has been removed, it
                     # might have been unfolded by the parent
                     # editor/document in the case of cloned editor
                     if deco.block == block:
                         # remove it and
                         self._block_decos.remove(deco)
                         self.editor.decorations.remove(deco)
                         del deco
                         break

    def get_parent_scopes(block):
        """
        Gets the list of hierarchical parent scopes of the current block.

        :param block: current block
        :return: list of QTextBlock
        """
        scopes = [block]
        scope = FoldScope.find_parent_scope(block)
        while scope is not None:
            ref = TextBlockHelper.get_fold_lvl(scopes[-1])
            if TextBlockHelper.get_fold_lvl(scope) < ref:
                # ignore sibling scopes
                scopes.append(scope)
            if scope.blockNumber() == 0:
                # stop
                scope = None
            else:
                # next parent
                scope = FoldScope.find_parent_scope(scope.previous())
        return reversed(scopes)

    def detect_fold_level(self, prev_block, block):
        ctext, ptext = self.stripped_texts(block, prev_block)
        if not self.editor.free_format:
            ctext = self.normalize_text(ctext)
            ptext = self.normalize_text(ptext)
        if regex.DIVISION.indexIn(ctext) != -1 and not ctext.lstrip().startswith('*'):
            return OFFSET_DIVISION
        elif regex.SECTION.indexIn(ctext) != -1 and not ctext.lstrip().startswith('*'):
            return OFFSET_SECTION
        else:
            # anywhere else, folding is mostly based on the indentation level
            indent = self.get_indent(ctext)
            pindent = self.get_indent(ptext)

            if ctext.strip().upper().startswith('END-') and self.is_valid(prev_block) and pindent > indent:
                # find previous block with the same indent, use it's fold level + 1 to include
                # the end-branch statement in the fold scope
                pblock = prev_block
                while self.is_valid(pblock) and (pindent != indent or len(ptext.strip()) == 0):
                    pblock = pblock.previous()
                    ptext = self.normalize_text(pblock.text())
                    pindent = self.get_indent(ptext)
                lvl = TextBlockHelper.get_fold_lvl(pblock.next())
            else:
                lvl = OFFSET_OTHER + indent

            # if not self.editor.free_format and (ctext.lstrip().startswith('-') or ctext.lstrip().startswith('*')):
            if not self.editor.free_format and (ctext.lstrip().startswith('-')):
                # use previous fold level
                lvl = TextBlockHelper.get_fold_lvl(prev_block)

            if not self.editor.free_format and ctext.strip().startswith('*'):
                if regex.DIVISION.indexIn(ptext) != -1 and not ptext.lstrip().startswith('*'):
                    lvl = OFFSET_SECTION
                elif regex.SECTION.indexIn(ptext) != -1 and not ptext.lstrip().startswith('*'):
                    return OFFSET_SECTION + 2
                else:
                    lvl = TextBlockHelper.get_fold_lvl(prev_block)

            return lvl

    def _highlight_surrounding_scopes(self, block):
        """
        Highlights the scopes surrounding the current fold scope.

        :param block: Block that starts the current fold scope.
        """
        scope = FoldScope(block)
        if (self._current_scope is None or
                self._current_scope.get_range() != scope.get_range()):
            self._current_scope = scope
            self._clear_scope_decos()
            # highlight surrounding parent scopes with a darker color
            start, end = scope.get_range()
            if not TextBlockHelper.get_fold_trigger_state(block):
                self._add_scope_decorations(block, start, end)

 def _on_item_state_changed(self, item):
     if self._updating:
         return
     if item == self._root_item:
         item_state = not item.isExpanded()
         if item_state:
             QtCore.QTimer.singleShot(
                 1, self._editor.folding_panel.collapse_all)
         else:
             QtCore.QTimer.singleShot(
                 1, self._editor.folding_panel.expand_all)
     else:
         block = item.data(0, QtCore.Qt.UserRole).block
         assert isinstance(item, QtWidgets.QTreeWidgetItem)
         item_state = not item.isExpanded()
         block_state = TextBlockHelper.get_fold_trigger_state(block)
         if item_state != block_state:
             self._editor.folding_panel.toggle_fold_trigger(block)

    def toggle_fold_trigger(self, block):
        """
        Toggle a fold trigger block (expand or collapse it).

        :param block: The QTextBlock to expand/collapse
        """
        if not TextBlockHelper.is_fold_trigger(block):
            return
        region = FoldScope(block)
        if region.collapsed:
            region.unfold()
            if self._mouse_over_line is not None:
                self._add_scope_decorations(
                    region._trigger, *region.get_range())
        else:
            region.fold()
            self._clear_scope_decos()
        self._refresh_editor_and_scrollbars()
        self.trigger_state_changed.emit(region._trigger, region.collapsed)

    def open(self, path, encoding=None, use_cached_encoding=True):
        encoding = self.detect_encoding(path)
        super(PyFileManager, self).open(
            path, encoding=encoding, use_cached_encoding=use_cached_encoding)
        try:
            folding_panel = self.editor.panels.get('FoldingPanel')
        except KeyError:
            pass
        else:
            # fold imports and/or docstrings
            blocks_to_fold = []
            sh = self.editor.syntax_highlighter

            if self.fold_imports and sh.import_statements:
                blocks_to_fold += sh.import_statements
            if self.fold_docstrings and sh.docstrings:
                blocks_to_fold += sh.docstrings

            for block in blocks_to_fold:
                if TextBlockHelper.is_fold_trigger(block):
                    folding_panel.toggle_fold_trigger(block)

        def convert(name, editor, to_collapse):
            ti = QtWidgets.QTreeWidgetItem()
            ti.setText(0, name.name)
            ti.setIcon(0, QtGui.QIcon(name.icon))
            name.block = editor.document().findBlockByNumber(name.line)
            ti.setData(0, QtCore.Qt.UserRole, name)
            block_data = name.block.userData()
            if block_data is None:
                block_data = TextBlockUserData()
                name.block.setUserData(block_data)
            block_data.tree_item = ti

            if to_collapse is not None and \
                    TextBlockHelper.get_fold_trigger_state(name.block):
                to_collapse.append(ti)

            for ch in name.children:
                ti_ch, to_collapse = convert(ch, editor, to_collapse)
                if ti_ch:
                    ti.addChild(ti_ch)
            return ti, to_collapse