lib/ios/ui/ui.nit

   1 # This file is part of NIT ( http://www.nitlanguage.org ).
   2 #
   3 # Licensed under the Apache License, Version 2.0 (the "License");
   4 # you may not use this file except in compliance with the License.
   5 # You may obtain a copy of the License at
   6 #
   7 #     http://www.apache.org/licenses/LICENSE-2.0
   8 #
   9 # Unless required by applicable law or agreed to in writing, software
  10 # distributed under the License is distributed on an "AS IS" BASIS,
  11 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 # See the License for the specific language governing permissions and
  13 # limitations under the License.
  14
  15 # Implementation of `app::ui` for iOS
  16 module ui
  17
  18 import app::ui
  19
  20 import ios
  21 import uikit
  22
  23 in "ObjC" `{
  24 // Objective-C object receiving callbacks from UI events
  25 @interface NitCallbackReference: NSObject
  26
  27         // Nit object target of the callbacks from UI events
  28         @property (nonatomic) View nit_view;
  29
  30         // Actual callback method
  31         -(void) nitOnEvent: (UIView*) sender;
  32 @end
  33
  34 @implementation NitCallbackReference
  35
  36         -(void) nitOnEvent: (UIView*) sender {
  37                 View_on_ios_event(self.nit_view);
  38         }
  39 @end
  40
  41 // Proxy for both delegates of UITableView relaying all callbacks to `nit_list_layout`
  42 @interface UITableViewAndDataSource: NSObject <UITableViewDelegate, UITableViewDataSource>
  43
  44         // Nit object receiving the callbacks
  45         @property TableView nit_list_layout;
  46
  47         // List of native views added to this list view from the Nit side
  48         @property NSMutableArray *views;
  49 @end
  50
  51 @implementation UITableViewAndDataSource
  52
  53         - (id)init
  54         {
  55                 self = [super init];
  56                 self.views = [[NSMutableArray alloc] initWithCapacity:8];
  57                 return self;
  58         }
  59
  60         - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
  61                 return TableView_number_of_sections_in_table_view(self.nit_list_layout, tableView);
  62         }
  63
  64         - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
  65                 return TableView_number_of_rows_in_section(self.nit_list_layout, tableView, section);
  66         }
  67
  68         - (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section {
  69                 return TableView_title_for_header_in_section(self.nit_list_layout, tableView, section);
  70         }
  71
  72         - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
  73                 return TableView_cell_for_row_at_index_path(self.nit_list_layout, tableView, indexPath);
  74         }
  75 @end
  76 `}
  77
  78 redef class App
  79         redef fun did_finish_launching_with_options
  80         do
  81                 app_delegate.window = new UIWindow
  82                 app_delegate.window.background_color = new UIColor.white_color
  83                 super
  84                 app_delegate.window.make_key_and_visible
  85                 return true
  86         end
  87
  88         private fun set_view_controller(window: UIWindow, native: UIViewController)
  89         in "ObjC" `{
  90                 // Set the required root view controller
  91                 UINavigationController *navController = (UINavigationController*)window.rootViewController;
  92
  93                 if (navController == NULL) {
  94                         navController = [[UINavigationController alloc]initWithRootViewController:native];
  95                         navController.edgesForExtendedLayout = UIRectEdgeNone;
  96
  97                         // Must be non-translucent for the controls to be placed under
  98                         // (as in Y axis) of the navigation bar.
  99                         navController.navigationBar.translucent = NO;
 100
 101                         window.rootViewController = navController;
 102                 }
 103                 else {
 104                         [navController pushViewController:native animated:YES];
 105                 }
 106
 107                 native.edgesForExtendedLayout = UIRectEdgeNone;
 108         `}
 109
 110         redef fun window=(window)
 111         do
 112                 set_view_controller(app_delegate.window, window.native)
 113                 super
 114         end
 115 end
 116
 117 redef class AppDelegate
 118
 119         # The main application window, must be set by `App::on_create`
 120         fun window: UIWindow in "ObjC" `{ return [self window]; `}
 121
 122         # The main application window, must be set by `App::on_create`
 123         fun window=(window: UIWindow) in "ObjC" `{ self.window = window; `}
 124 end
 125
 126 redef class Control
 127
 128         # Native implementation of this control
 129         fun native: NATIVE is abstract
 130
 131         # Type of the `native` implementation of this control
 132         type NATIVE: NSObject
 133 end
 134
 135 redef class View
 136         redef type NATIVE: UIView
 137
 138         redef var enabled = null is lazy
 139
 140         private fun on_ios_event do end
 141 end
 142
 143 redef class CompositeControl
 144
 145         redef fun remove(view)
 146         do
 147                 super
 148
 149                 if view isa View then
 150                         view.native.remove_from_superview
 151                 end
 152         end
 153 end
 154
 155 redef class Window
 156
 157         redef type NATIVE: UIViewController
 158         redef var native = new UIViewController
 159
 160         # Title of this window
 161         fun title: String do return native.title.to_s
 162
 163         # Set the title of this window
 164         fun title=(title: String) do native.title = title.to_nsstring
 165
 166         redef fun add(view)
 167         do
 168                 super
 169
 170                 var native_view = view.native
 171                 assert native_view isa UIView
 172
 173                 native.view = native_view
 174         end
 175 end
 176
 177 redef class Layout
 178
 179         redef type NATIVE: UIStackView
 180         redef var native = new UIStackView
 181
 182         init
 183         do
 184                 native.alignment = new UIStackViewAlignment.fill
 185                 native.distribution = new UIStackViewDistribution.fill_equally
 186
 187                 # TODO make customizable
 188                 native.spacing = 4.0
 189         end
 190
 191         redef fun add(view)
 192         do
 193                 super
 194
 195                 var native_view = view.native
 196                 assert native_view isa UIView
 197                 self.native.add_arranged_subview native_view
 198         end
 199 end
 200
 201 redef class HorizontalLayout
 202         redef init do native.axis = new UILayoutConstraintAxis.horizontal
 203 end
 204
 205 redef class VerticalLayout
 206         redef init do native.axis = new UILayoutConstraintAxis.vertical
 207 end
 208
 209 redef class Label
 210
 211         redef type NATIVE: UILabel
 212         redef var native = new UILabel
 213
 214         redef fun text=(text) do native.text = (text or else "").to_nsstring
 215         redef fun text do return native.text.to_s
 216
 217         redef fun size=(size)
 218         do
 219                 size = size or else 1.0
 220                 var points = 8.0 + size * 8.0
 221                 set_size_native(native, points)
 222         end
 223
 224         private fun set_size_native(native: UILabel, points: Float)
 225         in "ObjC" `{
 226                 native.font = [UIFont systemFontOfSize: points];
 227         `}
 228
 229         redef fun align=(align) do set_align_native(native, align or else 0.0)
 230
 231         private fun set_align_native(native: UILabel, align: Float)
 232         in "ObjC" `{
 233
 234                 if (align == 0.5)
 235                         native.textAlignment = NSTextAlignmentCenter;
 236                 else if (align < 0.5)
 237                         native.textAlignment = NSTextAlignmentLeft;
 238                 else//if (align > 0.5)
 239                         native.textAlignment = NSTextAlignmentRight;
 240         `}
 241 end
 242
 243 # On iOS, check boxes are a layout composed of a label and an `UISwitch`
 244 redef class CheckBox
 245
 246         redef type NATIVE: UIStackView
 247         redef fun native do return layout.native
 248
 249         # Root layout implementing this check box
 250         var layout = new HorizontalLayout(parent=self.parent)
 251
 252         # Label with the text
 253         var lbl = new Label(parent=layout)
 254
 255         # `UISwitch` acting as the real check box
 256         var ui_switch: UISwitch is noautoinit
 257
 258         redef fun on_ios_event do notify_observers new ToggleEvent(self)
 259
 260         init
 261         do
 262                 # Tweak the layout so it is centered
 263                 layout.native.distribution = new UIStackViewDistribution.fill_proportionally
 264                 layout.native.alignment = new UIStackViewAlignment.center
 265                 layout.native.layout_margins_relative_arrangement = true
 266
 267                 var s = new UISwitch
 268                 native.add_arranged_subview s
 269                 ui_switch = s
 270
 271                 ui_switch.set_callback self
 272         end
 273
 274         redef fun text=(text) do lbl.text = text
 275         redef fun text do return lbl.text
 276
 277         redef fun is_checked do return ui_switch.on
 278         redef fun is_checked=(value) do ui_switch.set_on_animated(value, true)
 279 end
 280
 281 redef class UISwitch
 282         # Register callbacks on this switch to be relayed to `sender`
 283         private fun set_callback(sender: View)
 284         import View.on_ios_event in "ObjC" `{
 285
 286                 NitCallbackReference *ncr = [[NitCallbackReference alloc] init];
 287                 ncr.nit_view = sender;
 288
 289                 // Pin the objects in both Objective-C and Nit GC
 290                 View_incr_ref(sender);
 291                 ncr = (__bridge NitCallbackReference*)CFBridgingRetain(ncr);
 292
 293                 [self addTarget:ncr action:@selector(nitOnEvent:)
 294                         forControlEvents:UIControlEventValueChanged];
 295         `}
 296 end
 297
 298 redef class TextInput
 299
 300         redef type NATIVE: UITextField
 301         redef var native = new UITextField
 302
 303         redef fun text=(text) do native.text = (text or else "").to_nsstring
 304         redef fun text do return native.text.to_s
 305
 306         redef fun is_password=(value)
 307         do
 308                 native.secure_text_entry = value or else false
 309                 super
 310         end
 311 end
 312
 313 redef class Button
 314
 315         redef type NATIVE: UIButton
 316         redef var native = new UIButton(new UIButtonType.system)
 317
 318         init do native.set_callback self
 319
 320         redef fun on_ios_event do notify_observers new ButtonPressEvent(self)
 321
 322         redef fun text=(text) do if text != null then native.title = text.to_nsstring
 323         redef fun text do return native.current_title.to_s
 324
 325         redef fun enabled=(enabled) do native.enabled = enabled or else true
 326         redef fun enabled do return native.enabled
 327 end
 328
 329 redef class UIButton
 330         # Register callbacks on this button to be relayed to `sender`
 331         private fun set_callback(sender: View)
 332         import View.on_ios_event in "ObjC" `{
 333
 334                 NitCallbackReference *ncr = [[NitCallbackReference alloc] init];
 335                 ncr.nit_view = sender;
 336
 337                 // Pin the objects in both Objective-C and Nit GC
 338                 View_incr_ref(sender);
 339                 ncr = (__bridge NitCallbackReference*)CFBridgingRetain(ncr);
 340
 341                 [self addTarget:ncr action:@selector(nitOnEvent:)
 342                         forControlEvents:UIControlEventTouchUpInside];
 343         `}
 344 end
 345
 346 # On iOS, implemented by a `UIStackView` inside a ` UIScrollView`
 347 redef class ListLayout
 348
 349         redef type NATIVE: UIScrollView
 350         redef var native = new UIScrollView
 351
 352         # Real container of the subviews, contained within `native`
 353         var native_stack_view = new UIStackView
 354
 355         init
 356         do
 357                 native_stack_view.translates_autoresizing_mask_into_constraits = false
 358                 native_stack_view.axis = new UILayoutConstraintAxis.vertical
 359                 native_stack_view.alignment = new UIStackViewAlignment.fill
 360                 native_stack_view.distribution = new UIStackViewDistribution.fill_equally
 361                 native_stack_view.spacing = 4.0
 362
 363                 native.add_subview native_stack_view
 364                 native_add_constraints(native, native_stack_view)
 365         end
 366
 367         private fun native_add_constraints(scroll_view: UIScrollView, stack_view: UIStackView) in "ObjC" `{
 368                 [scroll_view addConstraints:[NSLayoutConstraint
 369                         constraintsWithVisualFormat: @"V:|-8-[view]-8-|"
 370                         options: NSLayoutFormatAlignAllCenterX metrics: nil views: @{@"view": stack_view}]];
 371                 [scroll_view addConstraints:[NSLayoutConstraint
 372                         constraintsWithVisualFormat: @"H:|-8-[view]"
 373                         options: NSLayoutFormatAlignAllCenterX metrics: nil views: @{@"view": stack_view}]];
 374         `}
 375
 376         redef fun add(view)
 377         do
 378                 super
 379
 380                 if view isa View then
 381                         native_stack_view.add_arranged_subview view.native
 382                 end
 383         end
 384 end
 385
 386 # iOS specific layout using a `UITableView`, works only with simple children views
 387 class TableView
 388         super CompositeControl
 389
 390         redef type NATIVE: UITableView
 391         redef var native = new UITableView(new UITableViewStyle.plain)
 392
 393         init
 394         do
 395                 native.autoresizing_mask
 396                 native.assign_delegate_and_data_source self
 397         end
 398
 399         redef fun add(item)
 400         do
 401                 # Adding a view to a UITableView is a bit tricky.
 402                 #
 403                 # Items are added to the Objective-C view only by callbacks.
 404                 # We must store the sub views in local lists while waiting
 405                 # for the callbacks.
 406                 #
 407                 # As usual, we keep the Nity object in `items`.
 408                 # But we also keep their native counterparts in a list of
 409                 # the `UITableViewAndDataSource` set as `native.delegate`.
 410                 # Otherwise the native views could be freed by the Objective-C GC.
 411
 412                 # TODO use an adapter for the app.nit ListLayout closer to what exists
 413                 # on both iOS and Android, to support large data sets.
 414
 415                 if item isa View then
 416                         add_view_to_native_list(native, item.native)
 417                 end
 418
 419                 super
 420
 421                 # Force redraw and trigger callbacks
 422                 native.reload_data
 423         end
 424
 425         private fun add_view_to_native_list(native: UITableView, item: UIView) in "ObjC" `{
 426                 [((UITableViewAndDataSource*)native.delegate).views addObject:item];
 427         `}
 428
 429         private fun get_view_from_native_list(native: UITableView, index: Int): UIView in "ObjC" `{
 430                 return [((UITableViewAndDataSource*)native.delegate).views objectAtIndex:index];
 431         `}
 432
 433         # Number of sections in this view
 434         #
 435         # By default, we assume that all `items` are in a single section,
 436         # so there is only one section.
 437         #
 438         # iOS callback: `numberOfSectionsInTableView`
 439         protected fun number_of_sections_in_table_view(view: UITableView): Int
 440         do return 1
 441
 442         # Number of entries in `section`
 443         #
 444         # By default, we assume that all `items` are in a single section,
 445         # so no matter the section, this returns `items.length`.
 446         #
 447         # iOS callback: `numberOfRowsInSection`
 448         protected fun number_of_rows_in_section(view: UITableView, section: Int): Int
 449         do return items.length
 450
 451         # Title for `section`, return `new NSString.nil` for no title
 452         #
 453         # By default, this returns no title.
 454         #
 455         # iOS callback: `titleForHeaderInSection`
 456         protected fun title_for_header_in_section(view: UITableView, section: Int): NSString
 457         do return new NSString.nil
 458
 459         # Return a `UITableViewCell` for the item at `index_path`
 460         #
 461         # By default, we assume that all `items` are in a single section.
 462         # So no matter the depth of the `index_path`, this returns a cell with
 463         # the view at index part of `index_path`.
 464         #
 465         # iOS callback: `cellForRowAtIndexPath`
 466         protected fun cell_for_row_at_index_path(table_view: UITableView, index_path: NSIndexPath): UITableViewCell
 467         do
 468                 var reuse_id = "NitCell".to_nsstring
 469                 var cell = new UITableViewCell(reuse_id)
 470
 471                 # TODO if there is performance issues, reuse cells with
 472                 # the following code, but clear the cell before use.
 473
 474                 #var cell = table_view.dequeue_reusable_cell_with_identifier(reuse_id)
 475                 #if cell.address_is_null then cell = new UITableViewCell(reuse_id)
 476
 477                 var index = index_path.index_at_position(1)
 478                 var view_native = get_view_from_native_list(table_view, index)
 479                 var cv = cell.content_view
 480                 cv.add_subview view_native
 481
 482                 return cell
 483         end
 484 end
 485
 486 redef class UITableView
 487
 488         # Assign `list_view` as `delegate` and `dataSource`, and pin all references in both GCs
 489         private fun assign_delegate_and_data_source(list_view: TableView)
 490         import TableView.number_of_sections_in_table_view,
 491                TableView.number_of_rows_in_section,
 492                TableView.title_for_header_in_section,
 493                TableView.cell_for_row_at_index_path in "ObjC" `{
 494
 495                 UITableViewAndDataSource *objc_delegate = [[UITableViewAndDataSource alloc] init];
 496                 objc_delegate = (__bridge UITableViewAndDataSource*)CFBridgingRetain(objc_delegate);
 497
 498                 objc_delegate.nit_list_layout = list_view;
 499                 TableView_incr_ref(list_view);
 500
 501                 // Set our
 502                 self.delegate = objc_delegate;
 503                 self.dataSource = objc_delegate;
 504         `}
 505 end