# Source code for sdl2.ext.uisystem

    """User interface elements."""
    from .compat import isiterable, stringify
    from .ebs import System, World
    from .events import EventHandler
    from .sprite import Sprite
    from .. import events, mouse, keyboard, rect

    __all__ = [
        "RELEASED", "HOVERED", "PRESSED", "BUTTON", "CHECKBUTTON", "TEXTENTRY",
        "UIProcessor", "UIFactory"
    ]

    RELEASED = 0x0000
    HOVERED = 0x0001
    PRESSED = 0x0002

    BUTTON = 0x0001
    CHECKABLE = 0x0002
    CHECKBUTTON = (CHECKABLE | BUTTON)
    TEXTENTRY = 0x0004

    def _compose_button(obj):
        """Binds button attributes to the object, so it can be properly
        processed by the UIProcessor.

        Note: this is an internal helper method to avoid multiple
        inheritance and composition issues and should not be used by user
        code.
        """
        obj.uitype = BUTTON
        obj.state = RELEASED
        obj.motion = EventHandler(obj)
        obj.pressed = EventHandler(obj)
        obj.released = EventHandler(obj)
        obj.click = EventHandler(obj)
        obj.events = {
            events.SDL_MOUSEMOTION: obj.motion,
            events.SDL_MOUSEBUTTONDOWN: obj.pressed,
            events.SDL_MOUSEBUTTONUP: obj.released
            }

    def _compose_checkbutton(obj):
        """Binds check button attributes to the object, so it can be properly
        processed by the UIProcessor.

        Note: this is an internal helper method to avoid multiple
        inheritance and composition issues and should not be used by user
        code.
        """
        _compose_button(obj)
        obj.uitype = CHECKBUTTON
        obj.checked = False

    def _compose_textentry(obj):
        """Binds text entry attributes to the object, so it can be properly
        processed by the UIProcessor.

        Note: this is an internal helper method to avoid multiple
        inheritance and composition issues and should not be used by user
        code.
        """
        obj.uitype = TEXTENTRY
        obj.text = ""
        obj.motion = EventHandler(obj)
        obj.pressed = EventHandler(obj)
        obj.released = EventHandler(obj)
        obj.keydown = EventHandler(obj)
        obj.keyup = EventHandler(obj)
        obj.input = EventHandler(obj)
        obj.editing = EventHandler(obj)
        obj.events = {
            events.SDL_MOUSEMOTION: obj.motion,
            events.SDL_MOUSEBUTTONDOWN: obj.pressed,
            events.SDL_MOUSEBUTTONUP: obj.released,
            events.SDL_TEXTEDITING: obj.editing,
            events.SDL_TEXTINPUT: obj.input,
            events.SDL_KEYDOWN: obj.keydown,
            events.SDL_KEYUP: obj.keyup
            }

    class UIFactory(object):
        """A simple UI factory for creating GUI elements for software- or
        texture-based rendering."""
        def __init__(self, spritefactory, **kwargs):
            """Creates a new UIFactory.

            The additional kwargs will be stored internally and passed to the
            UI creation methods as arguments. Hence they can act as default
            arguments to be passed to each and every UI element to be
            created.
            """
            self.spritefactory = spritefactory
            self.default_args = kwargs

        def from_image(self, uitype, fname):
            """Creates a new UI element from the passed image file."""
            sprite = self.spritefactory.from_image(fname)
            if uitype == BUTTON:
                _compose_button(sprite)
            elif uitype == CHECKBUTTON:
                _compose_checkbutton(sprite)
            elif uitype == TEXTENTRY:
                _compose_textentry(sprite)
            else:
                del sprite
                raise ValueError("uitype must be a valid UI type identifier")
            return sprite

        def from_surface(self, uitype, surface, free=False):
            """Creates a new UI element from the passed SDL surface."""
            sprite = self.spritefactory.from_surface(surface, free)
            if uitype == BUTTON:
                _compose_button(sprite)
            elif uitype == CHECKBUTTON:
                _compose_checkbutton(sprite)
            elif uitype == TEXTENTRY:
                _compose_textentry(sprite)
            else:
                del sprite
                raise ValueError("uitype must be a valid UI type identifier")
            return sprite

        def from_object(self, uitype, obj):
            """Creates a new UI element from an arbitrary object."""
            sprite = self.spritefactory.from_object(obj)
            if uitype == BUTTON:
                _compose_button(sprite)
            elif uitype == CHECKBUTTON:
                _compose_checkbutton(sprite)
            elif uitype == TEXTENTRY:
                _compose_textentry(sprite)
            else:
                del sprite
                raise ValueError("uitype must be a valid UI type identifier")
            return sprite

        def from_color(self, uitype, color, size):
            """Creates a new UI element using a certain color."""
            sprite = self.spritefactory.from_color(color, size)
            if uitype == BUTTON:
                _compose_button(sprite)
            elif uitype == CHECKBUTTON:
                _compose_checkbutton(sprite)
            elif uitype == TEXTENTRY:
                _compose_textentry(sprite)
            else:
                del sprite
                raise ValueError("uitype must be a valid UI type identifier")
            return sprite

        def create_button(self, **kwargs):
            """Creates a new Sprite that can react on mouse events."""
            args = self.default_args.copy()
            args.update(kwargs)
            sprite = self.spritefactory.create_sprite(**args)
            _compose_button(sprite)
            return sprite

        def create_checkbutton(self, **kwargs):
            """Creates a new Sprite that can react on mouse events and
            retains its state."""
            args = self.default_args.copy()
            args.update(kwargs)
            sprite = self.spritefactory.create_sprite(**args)
            _compose_checkbutton(sprite)
            return sprite

        def create_text_entry(self, **kwargs):
            """Creates a new Sprite that can react on text input."""
            args = self.default_args.copy()
            args.update(kwargs)
            sprite = self.spritefactory.create_sprite(**args)
            _compose_textentry(sprite)
            return sprite

        def __repr__(self):
            return "UIFactory(spritefactory=%s, default_args=%s)" % \
                (self.spritefactory, self.default_args)

    class UIProcessor(System):
        """A processing system for user interface elements and events."""
        def __init__(self):
            """Creates a new UIProcessor."""
            super(UIProcessor, self).__init__()
            self.componenttypes = (Sprite,)
            self._nextactive = None
            self._activecomponent = None
            self.handlers = {
                events.SDL_MOUSEMOTION: self.mousemotion,
                events.SDL_MOUSEBUTTONDOWN: self.mousedown,
                events.SDL_MOUSEBUTTONUP: self.mouseup,
                events.SDL_TEXTINPUT: self.textinput
                }

        def activate(self, component):
            """Activates a control to receive input."""
            if self._activecomponent and self._activecomponent != component:
                self.deactivate(self._activecomponent)

            if (component.uitype & TEXTENTRY):
                area = rect.SDL_Rect(component.x, component.y,
                                     component.size[0], component.size[1])
                keyboard.SDL_SetTextInputRect(area)
                keyboard.SDL_StartTextInput()
            self._activecomponent = component

        def deactivate(self, component):
            """Deactivates the currently active control."""
            if component == self._activecomponent:
                if (self._activecomponent.uitype & TEXTENTRY):
                    keyboard.SDL_StopTextInput()
                self._activecomponent = None

        def passevent(self, component, event):
            """Passes the event to a component without any additional checks
            or restrictions.
            """
            component.events[event.type](event)

        def textinput(self, component, event):
            """Checks, if an active component is available and matches the
            passed component and passes the event on to that component."""
            if self._activecomponent == component:
                if (component.uitype & TEXTENTRY):
                    component.text += stringify(event.text.text, "utf-8")
                component.events[event.type](event)

        def mousemotion(self, component, event):
            """Checks, if the event's motion position is on the component
            and executes the component's event handlers on demand.

            If the motion event position is not within the area of the
            component, nothing will be done. In case the component is a
            Button, its state will be adjusted to reflect, if it is
            currently hovered or not.
            """
            x1, y1, x2, y2 = component.area
            if event.motion.x >= x1 and event.motion.x < x2 and \
                    event.motion.y >= y1 and event.motion.y < y2:
                # Within the area of the component, raise the event on it.
                component.events[event.type](event)
                if (component.uitype & BUTTON):
                    component.state |= HOVERED
            elif (component.uitype & BUTTON):
                # The mouse is not within the area of the button, reset the
                # state
                component.state &= ~HOVERED

        def mousedown(self, component, event):
            """Checks, if the event's button press position is on the
            component and executes the component's event handlers on demand.

            If the button press position is not within the area of the
            component, nothing will be done. In case the component is a
            Button, its state will be adjusted to reflect, if it is
            currently pressed or not. In case the component is a TextEntry and
            the pressed button is the primary mouse button, the component will
            be marked as the next control to activate for text input.
            """
            x1, y1, x2, y2 = component.area
            if event.button.x >= x1 and event.button.x < x2 and \
                    event.button.y >= y1 and event.button.y < y2:
                # Within the area of the component, raise the event on it.
                component.events[event.type](event)
                if (component.uitype & BUTTON):
                    component.state = PRESSED | HOVERED
                    if (component.uitype & CHECKABLE):
                        if event.button.button == mouse.SDL_BUTTON_LEFT:
                            component.checked = not component.checked
                # Since we loop over all components, and might deactivate
                # some, store it temporarily for later activation.
                self._nextactive = component
            elif (component.uitype & BUTTON):
                component.state &= ~PRESSED

        def mouseup(self, component, event):
            """Checks, if the event's button release position is on the
            component and executes the component's event handlers on demand.

            If the button release position is not within the area of the
            component, nothing will be done. In case the component is a
            Button, its state will be adjusted to reflect, whether it is
            hovered or not. If the button release followed a button press on
            the same component and if the button is the primary button, the
            click() event handler is invoked, if the component is a Button.
            """
            x1, y1, x2, y2 = component.area
            if event.button.x >= x1 and event.button.x < x2 and \
                    event.button.y >= y1 and event.button.y < y2:
                # Within the area of the component, raise the event on it.
                component.events[event.type](event)
                if (component.uitype & BUTTON):
                    if (component.state & PRESSED) == PRESSED:
                        # Was pressed already, now it is a click
                        component.click(event)
                    component.state = RELEASED | HOVERED
            elif (component.uitype & BUTTON):
                component.state &= ~HOVERED

        def dispatch(self, obj, event):
            """Passes an event to the given object.

            If obj is a World object, UI relevant components will receive
            the event, if they support the event type.

            If obj is a single object, obj.events MUST be a dictionary
            consisting of SDL event type identifiers and EventHandler
            instances bound to the object. obj also must have a 'uitype' attribute
            referring to the UI type of the object.
            If obj is an iterable, such as a list or set, every item within
            obj MUST feature an 'events' and 'uitype' attribute as described
            above.
            """
            if event is None:
                return

            handler = self.handlers.get(event.type, self.passevent)
            if isinstance(obj, World):
                for ctype in self.componenttypes:
                    items = obj.get_components(ctype)
                    items = [(v, e) for v in items for e in (event,)
                             if hasattr(v, "events") and hasattr(v, "uitype") \
                                and e.type in v.events]
                    if len(items) > 0:
                        arg1, arg2 = zip(*items)
                        map(handler, arg1, arg2)
            elif isiterable(obj):
                items = [(v, e) for v in obj for e in (event,)
                         if e.type in v.events]
                if len(items) > 0:
                    for v, e in items:
                        handler(v, e)
            elif event.type in obj.events:
                handler(obj, event)
            if self._nextactive is not None:
                self.activate(self._nextactive)
                self._nextactive = None

        def process(self, world, components):
            """The UIProcessor class does not implement the process() method
            by default. Instead it uses dispatch() to send events around to
            components.
            """
            pass

        def __repr__(self):
            return "UIProcessor()"