1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478
use color::Color;
use cursor;
use event;
use fnv;
use graph::{self, Graph};
use input;
use position::{self, Align, Dimensions, Direction, Padding, Point, Position, Range, Rect, Scalar};
use render;
use std;
use std::sync::atomic::{self, AtomicUsize};
use text;
use theme::Theme;
use utils;
use widget::{self, Widget};
/// A constructor type for building a `Ui` instance with a set of optional parameters.
pub struct UiBuilder {
/// The initial dimensions of the window in which the `Ui` exists.
pub window_dimensions: Dimensions,
/// The theme used to set default styling for widgets.
///
/// If this field is `None` when `build` is called, `Theme::default` will be used.
pub maybe_theme: Option<Theme>,
/// An estimation of the maximum number of widgets that will be used with this `Ui` instance.
///
/// This value is used to determine the size with which various collections should be
/// reserved. This may make the first cycle of widget instantiations more efficient as the
/// collections will not be required to grow dynamically. These collections include:
///
/// - the widget graph node and edge `Vec`s
/// - the `HashSet` used to track updated widgets
/// - the widget `DepthOrder` (a kind of toposort describing the order of widgets in their
/// rendering order).
///
/// If this field is `None` when `build` is called, these collections will be initialised with
/// no pre-reserved size and will instead grow organically as needed.
pub maybe_widgets_capacity: Option<usize>,
}
/// `Ui` is the most important type within Conrod and is necessary for rendering and maintaining
/// widget state.
/// # Ui Handles the following:
/// * Contains the state of all widgets which can be indexed via their widget::Id.
/// * Stores rendering state for each widget until the end of each render cycle.
/// * Contains the theme used for default styling of the widgets.
/// * Maintains the latest user input state (for mouse and keyboard).
/// * Maintains the latest window dimensions.
#[derive(Debug)]
pub struct Ui {
/// The theme used to set default styling for widgets.
pub theme: Theme,
/// An index into the root widget of the graph, representing the entire window.
pub window: widget::Id,
/// Handles aggregation of events and providing them to Widgets
global_input: input::Global,
/// Manages all fonts that have been loaded by the user.
pub fonts: text::font::Map,
/// The Widget cache, storing state for all widgets.
widget_graph: Graph,
/// The widget::Id of the widget that was last updated/set.
maybe_prev_widget_id: Option<widget::Id>,
/// The widget::Id of the last widget used as a parent for another widget.
maybe_current_parent_id: Option<widget::Id>,
/// The number of frames that will be used for the `redraw_count` when `need_redraw` is
/// triggered.
num_redraw_frames: u8,
/// Whether or not the `Ui` needs to be re-drawn to screen.
redraw_count: AtomicUsize,
/// A background color to clear the screen with before drawing if one was given.
maybe_background_color: Option<Color>,
/// The order in which widgets from the `widget_graph` are drawn.
depth_order: graph::DepthOrder,
/// The set of widgets that have been updated since the beginning of the `set_widgets` stage.
updated_widgets: fnv::FnvHashSet<widget::Id>,
/// The `updated_widgets` for the previous `set_widgets` stage.
///
/// We use this to compare against the newly generated `updated_widgets` to see whether or not
/// we require re-drawing.
prev_updated_widgets: fnv::FnvHashSet<widget::Id>,
/// Scroll events that have been emitted during a call to `Ui::set_widgets`. These are usually
/// emitted by some widget like the `Scrollbar`.
///
/// These events will be drained and pushed onto the end of the `global_input` event buffer at
/// the end of the `Ui::set_widgets` method. This ensures that the events are received by the
/// target widgets during the next call to `Ui::set_widgets`.
pending_scroll_events: Vec<event::Ui>,
/// Mouse cursor
mouse_cursor: cursor::MouseCursor,
// TODO: Remove the following fields as they should now be handled by `input::Global`.
/// Window width.
pub win_w: f64,
/// Window height.
pub win_h: f64,
}
/// A wrapper around the `Ui` that restricts the user from mutating the `Ui` in certain ways while
/// in the scope of the `Ui::set_widgets` function and within `Widget`s' `update` methods. Using
/// the `UiCell`, users may access the `Ui` immutably (via `Deref`) however they wish, however they
/// may only mutate the `Ui` via the `&mut self` methods provided by the `UiCell`.
///
/// The name came from its likening to a "jail cell for the `Ui`", as it restricts a user's access
/// to it. However, we realise that the name may also cause ambiguity with the std `Cell` and
/// `RefCell` types (which `UiCell` has nothing to do with). Thus, if you have a better name for
/// this type in mind, please let us know at the github repo via an issue or PR sometime before we
/// hit 1.0.0!
#[derive(Debug)]
pub struct UiCell<'a> {
/// A mutable reference to a **Ui**.
ui: &'a mut Ui,
}
/// Each time conrod is required to redraw the GUI, it must draw for at least the next three frames
/// to ensure that, in the case that graphics buffers are being swapped, we have filled each
/// buffer. Otherwise if we don't draw into each buffer, we will probably be subject to flickering.
pub const SAFE_REDRAW_COUNT: u8 = 3;
impl UiBuilder {
/// Begin building a new `Ui` instance.
///
/// Give the initial dimensions of the window within which the `Ui` will be instantiated as a
/// `Scalar` (DPI agnostic) value.
pub fn new(window_dimensions: Dimensions) -> Self {
UiBuilder {
window_dimensions: window_dimensions,
maybe_theme: None,
maybe_widgets_capacity: None,
}
}
/// The theme used to set default styling for widgets.
///
/// If this field is `None` when `build` is called, `Theme::default` will be used.
pub fn theme(mut self, value: Theme) -> Self {
self.maybe_theme = Some(value);
self
}
/// An estimation of the maximum number of widgets that will be used with this `Ui` instance.
///
/// This value is used to determine the size with which various collections should be
/// reserved. This may make the first cycle of widget instantiations more efficient as the
/// collections will not be required to grow dynamically. These collections include:
///
/// - the widget graph node and edge `Vec`s
/// - the `HashSet` used to track updated widgets
/// - the widget `DepthOrder` (a kind of toposort describing the order of widgets in their
/// rendering order).
///
/// If this field is `None` when `build` is called, these collections will be initialised with
/// no pre-reserved size and will instead grow organically as required.
pub fn widgets_capacity(mut self, value: usize) -> Self {
self.maybe_widgets_capacity = Some(value);
self
}
/// Build **Ui** from the given builder
pub fn build(self) -> Ui {
Ui::new(self)
}
}
impl Ui {
/// A new, empty **Ui**.
fn new(builder: UiBuilder) -> Self {
let UiBuilder {
window_dimensions,
maybe_widgets_capacity,
maybe_theme,
} = builder;
let (mut widget_graph, depth_order, updated_widgets) = maybe_widgets_capacity.map_or_else(
|| {
(
Graph::new(),
graph::DepthOrder::new(),
fnv::FnvHashSet::default(),
)
},
|n| {
(
Graph::with_node_capacity(n),
graph::DepthOrder::with_node_capacity(n),
std::collections::HashSet::with_capacity_and_hasher(
n,
fnv::FnvBuildHasher::default(),
),
)
},
);
let window = widget_graph.add_placeholder();
let prev_updated_widgets = updated_widgets.clone();
Ui {
widget_graph: widget_graph,
theme: maybe_theme.unwrap_or_else(|| Theme::default()),
fonts: text::font::Map::new(),
window: window,
win_w: window_dimensions[0],
win_h: window_dimensions[1],
maybe_prev_widget_id: None,
maybe_current_parent_id: None,
num_redraw_frames: SAFE_REDRAW_COUNT,
redraw_count: AtomicUsize::new(SAFE_REDRAW_COUNT as usize),
maybe_background_color: None,
depth_order: depth_order,
updated_widgets: updated_widgets,
prev_updated_widgets: prev_updated_widgets,
global_input: input::Global::new(),
pending_scroll_events: Vec::new(),
mouse_cursor: cursor::MouseCursor::Arrow,
}
}
/// Returns a `input::Widget` for the given widget
pub fn widget_input(&self, widget: widget::Id) -> input::Widget {
// If there's no rectangle for a given widget, then we use one with zero area.
// This means that the resulting `input::Widget` will not include any mouse events
// unless it has captured the mouse, since none will have occured over that area.
let rect = self.rect_of(widget).unwrap_or_else(|| {
let right_edge = self.win_w / 2.0;
let bottom_edge = self.win_h / 2.0;
Rect::from_xy_dim([right_edge, bottom_edge], [0.0, 0.0])
});
input::Widget::for_widget(widget, rect, &self.global_input)
}
/// The **Rect** for the widget at the given index.
///
/// Returns `None` if there is no widget for the given index.
pub fn rect_of(&self, id: widget::Id) -> Option<Rect> {
self.widget_graph.widget(id).map(|widget| widget.rect)
}
/// The absolute width of the widget at the given index.
///
/// Returns `None` if there is no widget for the given index.
pub fn w_of(&self, id: widget::Id) -> Option<Scalar> {
self.rect_of(id).map(|rect| rect.w())
}
/// The absolute height of the widget at the given index.
///
/// Returns `None` if there is no widget for the given index.
pub fn h_of(&self, id: widget::Id) -> Option<Scalar> {
self.rect_of(id).map(|rect| rect.h())
}
/// The absolute dimensions for the widget at the given index.
///
/// Returns `None` if there is no widget for the given index.
pub fn wh_of(&self, id: widget::Id) -> Option<Dimensions> {
self.rect_of(id).map(|rect| rect.dim())
}
/// The coordinates for the widget at the given index.
///
/// Returns `None` if there is no widget for the given index.
pub fn xy_of(&self, id: widget::Id) -> Option<Point> {
self.rect_of(id).map(|rect| rect.xy())
}
/// The `kid_area` of the widget at the given index.
///
/// Returns `None` if there is no widget for the given index.
pub fn kid_area_of(&self, id: widget::Id) -> Option<Rect> {
self.widget_graph
.widget(id)
.map(|widget| widget.kid_area.rect.padding(widget.kid_area.pad))
}
/// An index to the previously updated widget if there is one.
pub fn maybe_prev_widget(&self) -> Option<widget::Id> {
self.maybe_prev_widget_id
}
/// Borrow the **Ui**'s `widget_graph`.
pub fn widget_graph(&self) -> &Graph {
&self.widget_graph
}
/// Borrow the **Ui**'s set of updated widgets.
///
/// This set indicates which widgets have been instantiated since the beginning of the most
/// recent `Ui::set_widgets` call.
pub fn updated_widgets(&self) -> &fnv::FnvHashSet<widget::Id> {
&self.updated_widgets
}
/// Borrow the **Ui**'s set of updated widgets.
///
/// This set indicates which widgets have were instantiated during the previous call to
/// `Ui::set_widgets`.
pub fn prev_updated_widgets(&self) -> &fnv::FnvHashSet<widget::Id> {
&self.prev_updated_widgets
}
/// Produces a type that may be used to generate new unique `widget::Id`s.
///
/// See the [**widget::id::Generator**](../widget/id/struct.Generator.html) docs for details on
/// how to use this correctly.
pub fn widget_id_generator(&mut self) -> widget::id::Generator {
widget::id::Generator::new(&mut self.widget_graph)
}
/// Scroll the widget at the given index by the given offset amount.
///
/// The produced `Scroll` event will be applied upon the next call to `Ui::set_widgets`.
pub fn scroll_widget(&mut self, widget_id: widget::Id, offset: [Scalar; 2]) {
let (x, y) = (offset[0], offset[1]);
if x != 0.0 || y != 0.0 {
let event = event::Ui::Scroll(
Some(widget_id),
event::Scroll {
x: x,
y: y,
modifiers: self.global_input.current.modifiers,
},
)
.into();
self.global_input.push_event(event);
}
}
/// Determines which widget is currently under the mouse and sets it within the `Ui`'s
/// `input::Global`'s `input::State`.
///
/// If the `widget_under_mouse` has changed, this function will also update the
/// `widget_capturing_mouse`.
///
/// If the left mouse button is up, we assume that the widget directly under the
/// mouse cursor captures all input from the mouse.
///
/// If the left mouse button is down, we assume that the widget that was clicked
/// remains "pinned" and will continue to capture the mouse until it is
/// released.
///
/// Note: This function expects that `ui.global_input.current.mouse.xy` is up-to-date.
fn track_widget_under_mouse_and_update_capturing(&mut self) {
self.global_input.current.widget_under_mouse = graph::algo::pick_widgets(
&self.depth_order.indices,
self.global_input.current.mouse.xy,
)
.next(&self.widget_graph, &self.depth_order.indices, &self.theme);
// If MouseButton::Left is up and `widget_under_mouse` has changed, capture new widget
// under mouse.
if self.global_input.current.mouse.buttons.left().is_up() {
let widget_under_mouse = self.global_input.current.widget_under_mouse;
// Check to see if we need to uncapture a widget.
if let Some(idx) = self.global_input.current.widget_capturing_mouse {
if widget_under_mouse != Some(idx) {
let source = input::Source::Mouse;
let event = event::Ui::WidgetUncapturesInputSource(idx, source).into();
self.global_input.push_event(event);
self.global_input.current.widget_capturing_mouse = None;
}
}
// Check to see if there is a new widget capturing the mouse.
if self.global_input.current.widget_capturing_mouse.is_none() {
if let Some(idx) = widget_under_mouse {
let source = input::Source::Mouse;
let event = event::Ui::WidgetCapturesInputSource(idx, source).into();
self.global_input.push_event(event);
self.global_input.current.widget_capturing_mouse = Some(idx);
}
}
}
}
/// Handle raw window events and update the `Ui` state accordingly.
///
/// This occurs within several stages:
///
/// 1. Convert the user's given `event` to a `RawEvent` so that the `Ui` may use it.
/// 2. Interpret the `RawEvent` for higher-level `Event`s such as `DoubleClick`,
/// `WidgetCapturesKeyboard`, etc.
/// 3. Update the `Ui`'s `global_input` `State` accordingly, depending on the `RawEvent`.
/// 4. Store newly produced `event::Ui`s within the `global_input` so that they may be filtered
/// and fed to `Widget`s next time `Ui::set_widget` is called.
///
/// This method *drives* the `Ui` forward, and is what allows for using conrod's `Ui` with any
/// window event stream.
///
/// The given `event` must implement the **ToRawEvent** trait so that it can be converted to a
/// `RawEvent` that can be used by the `Ui`.
pub fn handle_event(&mut self, event: event::Input) {
use event::Input;
use input::state::mouse::Button as MouseButton;
use input::{Button, Key, ModifierKey, Motion};
// A function for filtering `ModifierKey`s.
fn filter_modifier(key: Key) -> Option<ModifierKey> {
match key {
Key::LCtrl | Key::RCtrl => Some(ModifierKey::CTRL),
Key::LShift | Key::RShift => Some(ModifierKey::SHIFT),
Key::LAlt | Key::RAlt => Some(ModifierKey::ALT),
Key::LGui | Key::RGui => Some(ModifierKey::GUI),
_ => None,
}
}
// Here we handle all user input given to conrod.
//
// Not only do we store the `Input` event as an `Event::Raw`, we also use them to
// interpret higher level events such as `Click` or `Drag`.
//
// Finally, we also ensure that the `current_state` is up-to-date.
self.global_input.push_event(event.clone().into());
match event {
// Some button was pressed, whether keyboard, mouse or some other device.
Input::Press(button_type) => match button_type {
// Check to see whether we need to (un)capture the keyboard or mouse.
Button::Mouse(mouse_button) => {
// Create a mouse `Press` event.
let mouse_xy = self.global_input.current.mouse.xy;
let press = event::Press {
button: event::Button::Mouse(mouse_button, mouse_xy),
modifiers: self.global_input.current.modifiers,
};
let widget = self.global_input.current.widget_capturing_mouse;
let press_event = event::Ui::Press(widget, press).into();
self.global_input.push_event(press_event);
if let MouseButton::Left = mouse_button {
// Check to see if we need to uncapture the keyboard.
if let Some(idx) = self.global_input.current.widget_capturing_keyboard {
if Some(idx) != self.global_input.current.widget_under_mouse {
let source = input::Source::Keyboard;
let event = event::Ui::WidgetUncapturesInputSource(idx, source);
self.global_input.push_event(event.into());
self.global_input.current.widget_capturing_keyboard = None;
}
}
// Check to see if we need to capture the keyboard.
if let Some(idx) = self.global_input.current.widget_under_mouse {
let source = input::Source::Keyboard;
let event = event::Ui::WidgetCapturesInputSource(idx, source);
self.global_input.push_event(event.into());
self.global_input.current.widget_capturing_keyboard = Some(idx);
}
}
// Keep track of pressed buttons in the current input::State.
let xy = self.global_input.current.mouse.xy;
let widget = self.global_input.current.widget_under_mouse;
self.global_input
.current
.mouse
.buttons
.press(mouse_button, xy, widget);
}
Button::Keyboard(key) => {
// Create a keyboard `Press` event.
let press = event::Press {
button: event::Button::Keyboard(key),
modifiers: self.global_input.current.modifiers,
};
let widget = self.global_input.current.widget_capturing_keyboard;
let press_event = event::Ui::Press(widget, press).into();
self.global_input.push_event(press_event);
// If some modifier key was pressed, add it to the current modifiers.
if let Some(modifier) = filter_modifier(key) {
self.global_input.current.modifiers.insert(modifier);
}
// If `Esc` was pressed, check to see if we need to cancel a `Drag` or
// uncapture a widget.
if let Key::Escape = key {
// TODO:
// 1. Cancel `Drag` if currently under way.
// 2. If mouse is captured due to pinning widget with left mouse button,
// cancel capturing.
}
}
_ => {}
},
// Some button was released.
//
// Checks for events in the following order:
// 1. Click
// 2. DoubleClick
// 2. WidgetUncapturesMouse
Input::Release(button_type) => match button_type {
Button::Mouse(mouse_button) => {
// Create a `Release` event.
let mouse_xy = self.global_input.current.mouse.xy;
let release = event::Release {
button: event::Button::Mouse(mouse_button, mouse_xy),
modifiers: self.global_input.current.modifiers,
};
let widget = self.global_input.current.widget_capturing_mouse;
let release_event = event::Ui::Release(widget, release).into();
self.global_input.push_event(release_event);
// Check for `Click` and `DoubleClick` events.
let down = self.global_input.current.mouse.buttons[mouse_button].if_down();
if let Some((_, widget)) = down {
// The widget that's being clicked.
let clicked_widget =
self.global_input
.current
.widget_under_mouse
.and_then(|released| {
widget.and_then(|pressed| {
if pressed == released {
Some(released)
} else {
None
}
})
});
let click = event::Click {
button: mouse_button,
xy: self.global_input.current.mouse.xy,
modifiers: self.global_input.current.modifiers,
};
let click_event = event::Ui::Click(clicked_widget, click).into();
self.global_input.push_event(click_event);
let now = instant::Instant::now();
let double_click =
self.global_input
.last_click
.and_then(|(last_time, last_click)| {
// If the button of this click is different to the button
// of last click, don't create a `DoubleClick`.
if click.button != last_click.button {
return None;
}
// If the mouse has moved since the last click, don't
// create a `DoubleClick`.
if click.xy != last_click.xy {
return None;
}
// If the duration since the last click is longer than the
// double_click_threshold, don't create a `DoubleClick`.
let duration = now.duration_since(last_time);
// TODO: Work out how to get this threshold from the user's
// system preferences.
let threshold = self.theme.double_click_threshold;
if duration >= threshold {
return None;
}
Some(event::DoubleClick {
button: click.button,
xy: click.xy,
modifiers: click.modifiers,
})
});
if let Some(double_click) = double_click {
// Reset the `last_click` to `None`, as to not register another
// `DoubleClick` on the next consecutive `Click`.
self.global_input.last_click = None;
let double_click_event =
event::Ui::DoubleClick(clicked_widget, double_click).into();
self.global_input.push_event(double_click_event);
} else {
// Set the `Click` that we just stored as the `last_click`.
self.global_input.last_click = Some((now, click));
}
}
// Uncapture widget capturing mouse if MouseButton::Left is down and
// widget_under_mouse != capturing widget.
if let MouseButton::Left = mouse_button {
if let Some(idx) = self.global_input.current.widget_capturing_mouse {
if Some(idx) != self.global_input.current.widget_under_mouse {
let source = input::Source::Mouse;
let event = event::Ui::WidgetUncapturesInputSource(idx, source);
self.global_input.push_event(event.into());
self.global_input.current.widget_capturing_mouse = None;
}
}
}
// Release the given mouse_button from the input::State.
self.global_input
.current
.mouse
.buttons
.release(mouse_button);
}
Button::Keyboard(key) => {
// Create a `Release` event.
let release = event::Release {
button: event::Button::Keyboard(key),
modifiers: self.global_input.current.modifiers,
};
let widget = self.global_input.current.widget_capturing_keyboard;
let release_event = event::Ui::Release(widget, release).into();
self.global_input.push_event(release_event);
// If a modifier key was released, remove it from the current set.
if let Some(modifier) = filter_modifier(key) {
self.global_input.current.modifiers.remove(modifier);
}
}
_ => (),
},
// The window was resized.
Input::Resize(w, h) => {
// Create a `WindowResized` event.
let (w, h) = (w as Scalar, h as Scalar);
let window_resized = event::Ui::WindowResized([w, h]).into();
self.global_input.push_event(window_resized);
self.win_w = w;
self.win_h = h;
self.needs_redraw();
self.track_widget_under_mouse_and_update_capturing();
}
// The mouse cursor was moved to a new position.
//
// Checks for events in the following order:
// 1. `Drag`
// 2. `WidgetUncapturesMouse`
// 3. `WidgetCapturesMouse`
Input::Motion(motion) => {
// Create a `Motion` event.
let move_ = event::Motion {
motion: motion,
modifiers: self.global_input.current.modifiers,
};
let widget = self.global_input.current.widget_capturing_mouse;
let move_event = event::Ui::Motion(widget, move_).into();
self.global_input.push_event(move_event);
match motion {
Motion::MouseCursor { x, y } => {
// Check for drag events.
let last_mouse_xy = self.global_input.current.mouse.xy;
let mouse_xy = [x, y];
let delta_xy = utils::vec2_sub(mouse_xy, last_mouse_xy);
// For each button that is down, trigger a drag event.
let buttons = self.global_input.current.mouse.buttons.clone();
for (btn, btn_xy, widget) in buttons.pressed() {
let total_delta_xy = utils::vec2_sub(mouse_xy, btn_xy);
let distance = (total_delta_xy[0] + total_delta_xy[1]).abs().sqrt();
if distance > self.theme.mouse_drag_threshold {
let event = event::Ui::Drag(
widget,
event::Drag {
button: btn,
origin: btn_xy,
from: last_mouse_xy,
to: mouse_xy,
delta_xy: delta_xy,
total_delta_xy: total_delta_xy,
modifiers: self.global_input.current.modifiers,
},
)
.into();
self.global_input.push_event(event);
}
}
// Update the position of the mouse within the global_input's
// input::State.
self.global_input.current.mouse.xy = mouse_xy;
self.track_widget_under_mouse_and_update_capturing();
}
// Some scrolling occurred (e.g. mouse scroll wheel).
Motion::Scroll { x, y } => {
let mut scrollable_widgets = {
let depth_order = &self.depth_order.indices;
let mouse_xy = self.global_input.current.mouse.xy;
graph::algo::pick_scrollable_widgets(depth_order, mouse_xy)
};
// Iterate through the scrollable widgets from top to bottom.
//
// A scroll event will be created for the first scrollable widget
// that hasn't already reached the bound of the scroll event's
// direction.
while let Some(idx) = scrollable_widgets.next(
&self.widget_graph,
&self.depth_order.indices,
&self.theme,
) {
let (kid_area, maybe_x_scroll, maybe_y_scroll) =
match self.widget_graph.widget(idx) {
Some(widget) => (
widget.kid_area,
widget.maybe_x_scroll_state,
widget.maybe_y_scroll_state,
),
None => continue,
};
fn offset_is_at_bound<A>(
scroll: &widget::scroll::State<A>,
additional_offset: Scalar,
) -> bool {
fn approx_eq(a: Scalar, b: Scalar) -> bool {
(a - b).abs() < 0.000001
}
if additional_offset.is_sign_positive() {
let max = utils::partial_max(
scroll.offset_bounds.start,
scroll.offset_bounds.end,
);
approx_eq(scroll.offset, max)
} else {
let min = utils::partial_min(
scroll.offset_bounds.start,
scroll.offset_bounds.end,
);
approx_eq(scroll.offset, min)
}
}
let mut scroll_x = false;
let mut scroll_y = false;
// Check whether the x axis is scrollable.
if x != 0.0 {
let new_scroll = widget::scroll::State::update(
self,
idx,
&kid_area,
maybe_x_scroll,
x,
);
if let Some(prev_scroll) = maybe_x_scroll {
let (prev_is_at_bound, new_is_at_bound) = (
offset_is_at_bound(&prev_scroll, x),
offset_is_at_bound(&new_scroll, x),
);
scroll_x = !prev_is_at_bound || !new_is_at_bound;
}
}
// Check whether the y axis is scrollable.
if y != 0.0 {
let new_scroll = widget::scroll::State::update(
self,
idx,
&kid_area,
maybe_y_scroll,
y,
);
if let Some(prev_scroll) = maybe_y_scroll {
let (prev_is_at_bound, new_is_at_bound) = (
offset_is_at_bound(&prev_scroll, y),
offset_is_at_bound(&new_scroll, y),
);
scroll_y = !prev_is_at_bound || !new_is_at_bound;
}
}
// Create a `Scroll` event if either axis is scrollable.
if scroll_x || scroll_y {
let event = event::Ui::Scroll(
Some(idx),
event::Scroll {
x: x,
y: y,
modifiers: self.global_input.current.modifiers,
},
)
.into();
self.global_input.push_event(event);
// Now that we've scrolled the top, scrollable widget,
// we're done with the loop.
break;
}
}
// If no scrollable widgets could be scrolled, emit the event to
// the widget that currently captures the mouse.
if x != 0.0 || y != 0.0 {
let widget = self.global_input.current.widget_capturing_mouse;
if let Some(idx) = widget {
if let Some(widget) = self.widget_graph.widget(idx) {
// Only create the event if the widget is not
// scrollable, as the event would have already been
// created within the above loop.
if widget.maybe_x_scroll_state.is_none()
&& widget.maybe_y_scroll_state.is_none()
{
let scroll = event::Scroll {
x: x,
y: y,
modifiers: self.global_input.current.modifiers,
};
let event = event::Ui::Scroll(Some(idx), scroll);
self.global_input.push_event(event.into());
}
}
}
}
// Now that there might be a different widget under the mouse, we
// must update the capturing state.
self.track_widget_under_mouse_and_update_capturing();
}
_ => (),
}
}
Input::Text(string) => {
// Create a `Text` event.
let text = event::Text {
string: string,
modifiers: self.global_input.current.modifiers,
};
let widget = self.global_input.current.widget_capturing_keyboard;
let text_event = event::Ui::Text(widget, text).into();
self.global_input.push_event(text_event);
}
Input::Touch(touch) => match touch.phase {
input::touch::Phase::Start => {
// Find the widget under the touch.
let widget_under_touch =
graph::algo::pick_widgets(&self.depth_order.indices, touch.xy).next(
&self.widget_graph,
&self.depth_order.indices,
&self.theme,
);
// The start of the touch interaction state to be stored.
let start = input::state::touch::Start {
time: instant::Instant::now(),
xy: touch.xy,
widget: widget_under_touch,
};
// The touch interaction state to be stored in the map.
let state = input::state::touch::Touch {
start: start,
xy: touch.xy,
widget: widget_under_touch,
};
// Insert the touch state into the map.
self.global_input.current.touch.insert(touch.id, state);
// Push touch event.
let event = event::Ui::Touch(widget_under_touch, touch);
self.global_input.push_event(event.into());
// Push capture event.
if let Some(widget) = widget_under_touch {
let source = input::Source::Touch(touch.id);
let event = event::Ui::WidgetCapturesInputSource(widget, source);
self.global_input.push_event(event.into());
}
}
input::touch::Phase::Move => {
// Update the widget under the touch and return the widget capturing the touch.
let widget = match self.global_input.current.touch.get_mut(&touch.id) {
Some(touch_state) => {
touch_state.widget =
graph::algo::pick_widgets(&self.depth_order.indices, touch.xy)
.next(
&self.widget_graph,
&self.depth_order.indices,
&self.theme,
);
touch_state.xy = touch.xy;
touch_state.start.widget
}
None => None,
};
let event = event::Ui::Touch(widget, touch);
self.global_input.push_event(event.into());
}
input::touch::Phase::Cancel => {
let widget = self
.global_input
.current
.touch
.remove(&touch.id)
.and_then(|t| t.start.widget);
let event = event::Ui::Touch(widget, touch);
self.global_input.push_event(event.into());
// Generate an "uncaptures" event if necessary.
if let Some(widget) = widget {
let source = input::Source::Touch(touch.id);
let event = event::Ui::WidgetUncapturesInputSource(widget, source);
self.global_input.push_event(event.into());
}
}
input::touch::Phase::End => {
let old_touch = self
.global_input
.current
.touch
.remove(&touch.id)
.map(|touch| touch);
let widget_capturing = old_touch.as_ref().and_then(|touch| touch.start.widget);
let event = event::Ui::Touch(widget_capturing, touch);
self.global_input.push_event(event.into());
// Create a `Tap` event.
//
// If the widget at the end of the touch is the same as the widget at the start
// of the touch, that widget receives the `Tap`.
let tapped_widget =
graph::algo::pick_widgets(&self.depth_order.indices, touch.xy)
.next(&self.widget_graph, &self.depth_order.indices, &self.theme)
.and_then(|widget| match Some(widget) == widget_capturing {
true => Some(widget),
false => None,
});
let tap = event::Tap {
id: touch.id,
xy: touch.xy,
};
let event = event::Ui::Tap(tapped_widget, tap);
self.global_input.push_event(event.into());
// Generate an "uncaptures" event if necessary.
if let Some(widget) = widget_capturing {
let source = input::Source::Touch(touch.id);
let event = event::Ui::WidgetUncapturesInputSource(widget, source);
self.global_input.push_event(event.into());
}
}
},
Input::Focus(focused) if focused == true => self.needs_redraw(),
Input::Focus(_focused) => (),
Input::Redraw => self.needs_redraw(),
}
}
/// Get an immutable reference to global input. Handles aggregation of events and providing them to Widgets
///
/// Can be used to access the current input state, e.g. which widgets are currently capturing inputs.
pub fn global_input(&self) -> &input::Global {
&self.global_input
}
/// Set keyboard capturing widget
pub fn keyboard_capture(&mut self, idx: widget::Id) {
let source = input::Source::Keyboard;
if self
.global_input
.current
.widget_capturing_keyboard
.is_some()
{
let event = event::Ui::WidgetUncapturesInputSource(idx, source);
self.global_input.push_event(event.into());
self.global_input.current.widget_capturing_keyboard = None;
}
let event = event::Ui::WidgetCapturesInputSource(idx, source).into();
self.global_input.push_event(event);
self.global_input.current.widget_capturing_keyboard = Some(idx);
}
/// Get the centred xy coords for some given `Dimension`s, `Position` and alignment.
///
/// If getting the xy for a specific widget, its `widget::Id` should be specified so that we
/// can also consider the scroll offset of the scrollable parent widgets.
///
/// The `place_on_kid_area` argument specifies whether or not **Place** **Position** variants
/// should target a **Widget**'s `kid_area`, or simply the **Widget**'s total area.
pub fn calc_xy(
&self,
maybe_id: Option<widget::Id>,
maybe_parent_id: Option<widget::Id>,
x_position: Position,
y_position: Position,
dim: Dimensions,
place_on_kid_area: bool,
) -> Point {
use utils::vec2_add;
// Retrieves the absolute **Scalar** position from the given position for a single axis.
//
// The axis used is specified by the given range_from_rect function which, given some
// **Rect**, returns the relevant **Range**.
fn abs_from_position<R, P>(
ui: &Ui,
maybe_parent_id: Option<widget::Id>,
position: Position,
dim: Scalar,
place_on_kid_area: bool,
range_from_rect: R,
start_and_end_pad: P,
) -> Scalar
where
R: FnOnce(Rect) -> Range,
P: FnOnce(Padding) -> Range,
{
let (relative, maybe_id) = match position {
Position::Absolute(abs) => return abs,
Position::Relative(relative, maybe_id) => (relative, maybe_id),
};
match relative {
position::Relative::Scalar(scalar) => maybe_id
.or(ui.maybe_prev_widget_id)
.or(Some(ui.window.into()))
.and_then(|idx| ui.rect_of(idx).map(range_from_rect))
.map(|other_range| other_range.middle() + scalar)
.unwrap_or(scalar),
position::Relative::Direction(direction, amt) => maybe_id
.or(ui.maybe_prev_widget_id)
.and_then(|idx| ui.rect_of(idx).map(range_from_rect))
.map(|other_range| {
let range = Range::from_pos_and_len(0.0, dim);
match direction {
Direction::Forwards => range.align_after(other_range).middle() + amt,
Direction::Backwards => range.align_before(other_range).middle() - amt,
}
})
.unwrap_or_else(|| match direction {
Direction::Forwards => amt,
Direction::Backwards => -amt,
}),
position::Relative::Align(align) => maybe_id
.or(ui.maybe_prev_widget_id)
.or(Some(ui.window.into()))
.and_then(|idx| ui.rect_of(idx).map(range_from_rect))
.map(|other_range| {
let range = Range::from_pos_and_len(0.0, dim);
match align {
Align::Start => range.align_start_of(other_range).middle(),
Align::Middle => other_range.middle(),
Align::End => range.align_end_of(other_range).middle(),
}
})
.unwrap_or(0.0),
position::Relative::Place(place) => {
let parent_id = maybe_id
.or(maybe_parent_id)
.or(ui.maybe_current_parent_id)
.unwrap_or(ui.window.into());
let maybe_area = match place_on_kid_area {
true => ui
.widget_graph
.widget(parent_id)
.map(|w| w.kid_area)
.map(|k| (range_from_rect(k.rect), start_and_end_pad(k.pad))),
false => ui
.rect_of(parent_id)
.map(|rect| (range_from_rect(rect), Range::new(0.0, 0.0))),
};
maybe_area
.map(|(parent_range, pad)| {
let range = Range::from_pos_and_len(0.0, dim);
let parent_range = parent_range.pad_start(pad.start).pad_end(pad.end);
match place {
position::Place::Start(maybe_mgn) => {
range.align_start_of(parent_range).middle()
+ maybe_mgn.unwrap_or(0.0)
}
position::Place::Middle => parent_range.middle(),
position::Place::End(maybe_mgn) => {
range.align_end_of(parent_range).middle()
- maybe_mgn.unwrap_or(0.0)
}
}
})
.unwrap_or(0.0)
}
}
}
fn x_range(rect: Rect) -> Range {
rect.x
}
fn y_range(rect: Rect) -> Range {
rect.y
}
fn x_pad(pad: Padding) -> Range {
pad.x
}
fn y_pad(pad: Padding) -> Range {
pad.y
}
let x = abs_from_position(
self,
maybe_parent_id,
x_position,
dim[0],
place_on_kid_area,
x_range,
x_pad,
);
let y = abs_from_position(
self,
maybe_parent_id,
y_position,
dim[1],
place_on_kid_area,
y_range,
y_pad,
);
let xy = [x, y];
// Add the widget's parents' total combined scroll offset to the given xy.
maybe_id
.map(|idx| vec2_add(xy, graph::algo::scroll_offset(&self.widget_graph, idx)))
.unwrap_or(xy)
}
/// A function within which all widgets are instantiated by the user, normally situated within
/// the "update" stage of an event loop.
pub fn set_widgets(&mut self) -> UiCell {
self.maybe_prev_widget_id = None;
self.maybe_current_parent_id = None;
// Move the previous `updated_widgets` to `prev_updated_widgets` and clear
// `updated_widgets` so that we're ready to store the newly updated widgets.
{
let Ui {
ref mut updated_widgets,
ref mut prev_updated_widgets,
..
} = *self;
std::mem::swap(updated_widgets, prev_updated_widgets);
updated_widgets.clear();
}
let mut ui_cell = UiCell { ui: self };
// Instantiate the root `Window` `Widget`.
//
// This widget acts as the parent-most widget and root node for the Ui's `widget_graph`,
// upon which all other widgets are placed.
{
use {color, Borderable, Colorable, Positionable};
type Window = widget::BorderedRectangle;
Window::new([ui_cell.win_w, ui_cell.win_h])
.no_parent()
.x_y(0.0, 0.0)
.border(0.0)
.border_color(color::BLACK.alpha(0.0))
.color(
ui_cell
.maybe_background_color
.unwrap_or(color::BLACK.alpha(0.0)),
)
.set(ui_cell.window, &mut ui_cell);
}
ui_cell.ui.maybe_current_parent_id = Some(ui_cell.window.into());
ui_cell.set_mouse_cursor(cursor::MouseCursor::Arrow);
ui_cell
}
/// Set the number of frames that the `Ui` should draw in the case that `needs_redraw` is
/// called. The default is `3` (see the SAFE_REDRAW_COUNT docs for details).
pub fn set_num_redraw_frames(&mut self, num_frames: u8) {
self.num_redraw_frames = num_frames;
}
/// Tells the `Ui` that it needs to re-draw everything. It does this by setting the redraw
/// count to `num_redraw_frames`. See the docs for `set_num_redraw_frames`, SAFE_REDRAW_COUNT
/// or `draw_if_changed` for more info on how/why the redraw count is used.
pub fn needs_redraw(&self) {
self.redraw_count
.store(self.num_redraw_frames as usize, atomic::Ordering::Relaxed);
}
/// The first of the `Primitives` yielded by `Ui::draw` or `Ui::draw_if_changed` will always
/// be a `Rectangle` the size of the window in which conrod is hosted.
///
/// This method sets the colour with which this `Rectangle` is drawn (the default being
/// `conrod::color::TRANSPARENT`.
pub fn clear_with(&mut self, color: Color) {
self.maybe_background_color = Some(color);
}
/// Draw the `Ui` in it's current state.
///
/// NOTE: If you don't need to redraw your conrod GUI every frame, it is recommended to use the
/// `Ui::draw_if_changed` method instead.
pub fn draw(&self) -> render::Primitives {
let Ui {
ref redraw_count,
ref widget_graph,
ref depth_order,
ref theme,
ref fonts,
win_w,
win_h,
..
} = *self;
// Use the depth_order indices as the order for drawing.
let indices = &depth_order.indices;
// We're about to draw everything, so take one from the redraw count.
let remaining_redraws = redraw_count.load(atomic::Ordering::Relaxed);
if remaining_redraws > 0 {
redraw_count.store(remaining_redraws - 1, atomic::Ordering::Relaxed);
}
render::Primitives::new(widget_graph, indices, theme, fonts, [win_w, win_h])
}
/// Same as the `Ui::draw` method, but *only* draws if the `redraw_count` is greater than 0.
///
/// The `redraw_count` is set to `SAFE_REDRAW_COUNT` whenever a `Widget` indicates that it
/// needs to be re-drawn.
///
/// It can also be triggered manually by the user using the `Ui::needs_redraw` method.
///
/// This method is generally preferred over `Ui::draw` as it requires far less CPU usage, only
/// redrawing to the screen if necessary.
///
/// Note that when `Ui::needs_redraw` is triggered, it sets the `redraw_count` to 3 by default.
/// This ensures that conrod is drawn to each buffer in the case that there is buffer swapping
/// happening. Let us know if you need finer control over this and we'll expose a way for you
/// to set the redraw count manually.
pub fn draw_if_changed(&self) -> Option<render::Primitives> {
if self.has_changed() {
return Some(self.draw());
}
None
}
/// Returns if the redraw_count is greater than 0 and thus draw_if_changed would draw
/// See `Ui::draw_if_changed` for when this is triggered
pub fn has_changed(&self) -> bool {
self.redraw_count.load(atomic::Ordering::Relaxed) > 0
}
/// The **Rect** that bounds the kids of the widget with the given index.
pub fn kids_bounding_box(&self, id: widget::Id) -> Option<Rect> {
graph::algo::kids_bounding_box(&self.widget_graph, &self.prev_updated_widgets, id)
}
/// The **Rect** that represents the maximum fully visible area for the widget with the given
/// index, including consideration of cropped scroll area.
///
/// Otherwise, return None if the widget is not visible.
pub fn visible_area(&self, id: widget::Id) -> Option<Rect> {
graph::algo::cropped_area_of_widget(&self.widget_graph, id)
}
/// Get mouse cursor state.
pub fn mouse_cursor(&self) -> cursor::MouseCursor {
self.mouse_cursor
}
}
impl<'a> UiCell<'a> {
/// A reference to the `Theme` that is currently active within the `Ui`.
pub fn theme(&self) -> &Theme {
&self.ui.theme
}
/// A convenience method for borrowing the `Font` for the given `Id` if it exists.
pub fn font(&self, id: text::font::Id) -> Option<&text::Font> {
self.ui.fonts.get(id)
}
/// Returns the dimensions of the window
pub fn window_dim(&self) -> Dimensions {
[self.ui.win_w, self.ui.win_h]
}
/// Returns an immutable reference to the `input::Global` of the `Ui`.
///
/// All coordinates here will be relative to the center of the window.
pub fn global_input(&self) -> &input::Global {
&self.ui.global_input
}
/// Returns a `input::Widget` with input events for the widget.
///
/// All coordinates in the `input::Widget` will be relative to the widget at the given index.
pub fn widget_input(&self, id: widget::Id) -> input::Widget {
self.ui.widget_input(id)
}
/// Produces a type that may be used to generate new unique `widget::Id`s.
///
/// See the [**widget::id::Generator**](../widget/id/struct.Generator.html) docs for details on
/// how to use this correctly.
pub fn widget_id_generator(&mut self) -> widget::id::Generator {
self.ui.widget_id_generator()
}
/// The **Rect** that bounds the kids of the widget with the given index.
///
/// Returns `None` if the widget has no children or if there's is no widget for the given index.
pub fn kids_bounding_box(&self, id: widget::Id) -> Option<Rect> {
self.ui.kids_bounding_box(id)
}
/// Scroll the widget at the given index by the given offset amount.
///
/// The produced `Scroll` event will be pushed to the `pending_scroll_events` and will be
/// applied to the widget during the next call to `Ui::set_widgets`.
pub fn scroll_widget(&mut self, id: widget::Id, offset: [Scalar; 2]) {
let (x, y) = (offset[0], offset[1]);
if x != 0.0 || y != 0.0 {
let event = event::Ui::Scroll(
Some(id),
event::Scroll {
x: x,
y: y,
modifiers: self.ui.global_input.current.modifiers,
},
);
self.ui.pending_scroll_events.push(event);
}
}
/// Sets the mouse cursor
pub fn set_mouse_cursor(&mut self, cursor: cursor::MouseCursor) {
self.ui.mouse_cursor = cursor;
}
}
impl<'a> Drop for UiCell<'a> {
fn drop(&mut self) {
// We'll need to re-draw if we have gained or lost widgets.
let changed = self.ui.updated_widgets != self.ui.prev_updated_widgets;
if changed {
self.ui.needs_redraw();
}
// Update the **DepthOrder** so that it reflects the **Graph**'s current state.
{
let Ui {
ref widget_graph,
ref mut depth_order,
window,
ref updated_widgets,
..
} = *self.ui;
depth_order.update(widget_graph, window, updated_widgets);
}
// Reset the global input state. Note that this is the **only** time this should be called.
self.ui.global_input.clear_events_and_update_start_state();
// Update which widget is under the cursor.
if changed {
self.ui.track_widget_under_mouse_and_update_capturing();
}
// Move all pending `Scroll` events that have been produced since the start of this method
// into the `global_input` event buffer.
for scroll_event in self.ui.pending_scroll_events.drain(0..) {
self.ui.global_input.push_event(scroll_event.into());
}
}
}
impl<'a> ::std::ops::Deref for UiCell<'a> {
type Target = Ui;
fn deref(&self) -> &Ui {
self.ui
}
}
impl<'a> AsRef<Ui> for UiCell<'a> {
fn as_ref(&self) -> &Ui {
&self.ui
}
}
/// A function for retrieving the `&mut Ui<B>` from a `UiCell<B>`.
///
/// This function is only for internal use to allow for some `Ui` type acrobatics in order to
/// provide a nice *safe* API for the user.
pub fn ref_mut_from_ui_cell<'a, 'b: 'a>(ui_cell: &'a mut UiCell<'b>) -> &'a mut Ui {
ui_cell.ui
}
/// A mutable reference to the given `Ui`'s widget `Graph`.
pub fn widget_graph_mut(ui: &mut Ui) -> &mut Graph {
&mut ui.widget_graph
}
/// Infer a widget's `Depth` parent by examining it's *x* and *y* `Position`s.
///
/// When a different parent may be inferred from either `Position`, the *x* `Position` is favoured.
pub fn infer_parent_from_position(ui: &Ui, x: Position, y: Position) -> Option<widget::Id> {
use position::Relative::{Align, Direction, Place, Scalar};
use Position::Relative;
match (x, y) {
(Relative(Place(_), maybe_parent_id), _) | (_, Relative(Place(_), maybe_parent_id)) => {
maybe_parent_id
}
(Relative(Direction(_, _), maybe_id), _)
| (_, Relative(Direction(_, _), maybe_id))
| (Relative(Align(_), maybe_id), _)
| (_, Relative(Align(_), maybe_id))
| (Relative(Scalar(_), maybe_id), _)
| (_, Relative(Scalar(_), maybe_id)) => maybe_id
.or(ui.maybe_prev_widget_id)
.and_then(|idx| ui.widget_graph.depth_parent(idx)),
_ => None,
}
}
/// Attempts to infer the parent of a widget from its *x*/*y* `Position`s and the current state of
/// the `Ui`.
///
/// If no parent can be inferred via the `Position`s, the `maybe_current_parent_id` will be used.
///
/// If `maybe_current_parent_id` is `None`, the `Ui`'s `window` widget will be used.
///
/// **Note:** This function does not check whether or not using the `window` widget would cause a
/// cycle.
pub fn infer_parent_unchecked(ui: &Ui, x_pos: Position, y_pos: Position) -> widget::Id {
infer_parent_from_position(ui, x_pos, y_pos)
.or(ui.maybe_current_parent_id)
.unwrap_or(ui.window.into())
}
/// Cache some `PreUpdateCache` widget data into the widget graph.
/// Set the widget that is being cached as the new `prev_widget`.
/// Set the widget's parent as the new `current_parent`.
pub fn pre_update_cache(ui: &mut Ui, widget: widget::PreUpdateCache) {
ui.maybe_prev_widget_id = Some(widget.id);
ui.maybe_current_parent_id = widget.maybe_parent_id;
let widget_id = widget.id;
ui.widget_graph
.pre_update_cache(ui.window, widget, ui.updated_widgets.len());
// Add the widget's `widget::Id` to the set of updated widgets.
ui.updated_widgets.insert(widget_id);
}
/// Cache some `PostUpdateCache` widget data into the widget graph.
/// Set the widget that is being cached as the new `prev_widget`.
/// Set the widget's parent as the new `current_parent`.
pub fn post_update_cache<W>(ui: &mut Ui, widget: widget::PostUpdateCache<W>)
where
W: Widget,
W::State: 'static,
W::Style: 'static,
{
ui.maybe_prev_widget_id = Some(widget.id);
ui.maybe_current_parent_id = widget.maybe_parent_id;
ui.widget_graph.post_update_cache(widget);
}