Source code for enamlnative.ios.app

"""
Copyright (c) 2017-2022, CodeLV.

Distributed under the terms of the MIT License.

The full license is in the file LICENSE, distributed with this software.

"""
import ctypes
from ctypes.util import find_library
from atom.api import Float, Typed, Value
from enaml.application import ProxyResolver
from enamlnative.core.app import BridgedApplication
from . import factories
from .bridge import ObjcBridgeObject, ObjcMethod


[docs]class ENBridge(ObjcBridgeObject):
    """Access ENBridge.m using ctypes.

    Based on:
    https://stackoverflow.com/questions/1490039/
    calling-objective-c-functions-from-python#1490644

    """

    #: Objc library
    objc = Value()

    #: Bridge.m access via ctypes
    bridge = Value()

    def _default_objc(self):
        """Load the objc library using ctypes."""
        objc = ctypes.cdll.LoadLibrary(find_library("objc"))
        objc.objc_getClass.restype = ctypes.c_void_p
        objc.sel_registerName.restype = ctypes.c_void_p
        objc.objc_msgSend.restype = ctypes.c_void_p
        objc.objc_msgSend.argtypes = [ctypes.c_void_p, ctypes.c_void_p]
        return objc

    def _default_bridge(self):
        """Get an instance of the ENBridge object using ctypes."""
        objc = self.objc
        ENBridge = objc.objc_getClass("ENBridge")
        return objc.objc_msgSend(ENBridge, objc.sel_registerName("instance"))

[docs]    def processEvents(self, data):
        """Sends msgpack data to the ENBridge instance
        by calling the processEvents method via ctypes."""
        objc = self.objc
        bridge = self.bridge
        #: This must come after the above as it changes the arguments!
        objc.objc_msgSend.argtypes = [
            ctypes.c_void_p,
            ctypes.c_void_p,
            ctypes.c_char_p,
            ctypes.c_int,
        ]
        objc.objc_msgSend(
            bridge, objc.sel_registerName("processEvents:length:"), data, len(data)
        )

    #: Add a target to a UIControl that invokes a python callback
    addTarget = ObjcMethod(
        "UIControl",
        dict(forControlEvents="enum"),  # ""UIControlEvents"),
        dict(andCallback=int),
        dict(usingMethod="NSString"),
        dict(withValues="NSArray"),
    )


[docs]class AppDelegate(ObjcBridgeObject):
    pass


[docs]class ViewController(ObjcBridgeObject):
    displayView = ObjcMethod("UIView")


[docs]class IPhoneApplication(BridgedApplication):
    """An iPhone implementation of an Enaml Native BridgedApplication.

    An IPhoneApplication uses the native iOS widget toolkit to implement an
    Enaml UI that runs in the local process.

    Since Objective-C can easily use the Python C-API, much if this classes
    implementation is done directly. For instance, the AppEventListener API is
    implemented directly in Objective-C (in Bridge.m) and invokes methods
    on this directly.

    """

    #: AppDelegate widget
    app_delegate = Typed(AppDelegate)

    #: ViewControler
    view_controller = Typed(ViewController)

    #: ENBridge
    bridge = Typed(ENBridge)

    #: Pixel density of the device
    #: Loaded immediately as this is used often.
    dp = Float()

    # --------------------------------------------------------------------------
    # Defaults
    # --------------------------------------------------------------------------
    def _default_app_delegate(self):
        """Return a bridge object reference to the AppDelegate
        this bridge sets this using a special id of -1

        """
        return AppDelegate(__id__=-1)

    def _default_view_controller(self):
        """Return a bridge object reference to the ViewController
        the bridge sets this using a special id of -2

        """
        return ViewController(__id__=-2)

    def _default_bridge(self):
        """Access the bridge using ctypes. Everything else should use
        bridge objects.

        """
        return ENBridge(__id__=-4)

    def _default_dp(self):
        return 1.0

    # -------------------------------------------------------------------------
    # IPhoneApplication Constructor
    # -------------------------------------------------------------------------
[docs]    def __init__(self, *args, **kwargs):
        """Initialize a IPhoneApplication."""
        super().__init__(*args, **kwargs)
        self.resolver = ProxyResolver(factories=factories.IOS_FACTORIES)

    # -------------------------------------------------------------------------
    # Bridge API Implementation
    # -------------------------------------------------------------------------
[docs]    def show_view(self):
        """Show the current `app.view`. This will fade out the previous
        with the new view.
        """
        self.view_controller.displayView(self.get_view())

[docs]    def dispatch_events(self, data):
        """Send the data to the Native application for processing"""
        self.bridge.processEvents(data)

    # -------------------------------------------------------------------------
    # Plugin API Implementation
    # -------------------------------------------------------------------------
[docs]    def load_plugin_factories(self):
        """Add any plugin toolkit widgets to the ANDROID_FACTORIES"""
        for plugin in self.get_plugins(group="enaml_native_ios_factories"):
            get_factories = plugin.load()
            PLUGIN_FACTORIES = get_factories()
            factories.IOS_FACTORIES.update(PLUGIN_FACTORIES)