src/Tizen.NUI.Components/Controls/Scrollbar.cs

   1 /*
   2  * Copyright(c) 2020 Samsung Electronics Co., Ltd.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  * http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  *
  16  */
  17 using System;
  18 using System.ComponentModel;
  19 using Tizen.NUI.BaseComponents;
  20 using Tizen.NUI.Binding;
  21
  22 namespace Tizen.NUI.Components
  23 {
  24     /// <summary>
  25     /// The Scrollbar is a component that contains track and thumb to indicate the current scrolled position of a scrollable object.
  26     /// </summary>
  27     [EditorBrowsable(EditorBrowsableState.Never)]
  28     public class Scrollbar : ScrollbarBase
  29     {
  30         #region Fields
  31
  32         /// <summary>Bindable property of TrackThickness</summary>
  33         [EditorBrowsable(EditorBrowsableState.Never)]
  34         public static readonly BindableProperty TrackThicknessProperty = BindableProperty.Create(nameof(TrackThickness), typeof(float), typeof(Scrollbar), default(float), propertyChanged: (bindable, oldValue, newValue) =>
  35         {
  36             var instance = ((Scrollbar)bindable);
  37             var thickness = (float?)newValue;
  38
  39             ((ScrollbarStyle)instance.viewStyle).TrackThickness = thickness;
  40             instance.UpdateTrackThickness(thickness ?? 0);
  41         },
  42         defaultValueCreator: (bindable) =>
  43         {
  44             return ((ScrollbarStyle)((Scrollbar)bindable).viewStyle)?.TrackThickness ?? 0;
  45         });
  46
  47         /// <summary>Bindable property of ThumbThickness</summary>
  48         [EditorBrowsable(EditorBrowsableState.Never)]
  49         public static readonly BindableProperty ThumbThicknessProperty = BindableProperty.Create(nameof(ThumbThickness), typeof(float), typeof(Scrollbar), default(float), propertyChanged: (bindable, oldValue, newValue) =>
  50         {
  51             var instance = ((Scrollbar)bindable);
  52             var thickness = (float?)newValue;
  53
  54             ((ScrollbarStyle)instance.viewStyle).ThumbThickness = thickness;
  55             instance.UpdateThumbThickness(thickness ?? 0);
  56         },
  57         defaultValueCreator: (bindable) =>
  58         {
  59             return ((ScrollbarStyle)((Scrollbar)bindable).viewStyle)?.ThumbThickness ?? 0;
  60         });
  61
  62         /// <summary>Bindable property of TrackColor</summary>
  63         [EditorBrowsable(EditorBrowsableState.Never)]
  64         public static readonly BindableProperty TrackColorProperty = BindableProperty.Create(nameof(TrackColor), typeof(Color), typeof(Scrollbar), null, propertyChanged: (bindable, oldValue, newValue) =>
  65         {
  66             var instance = ((Scrollbar)bindable);
  67             var color = (Color)newValue;
  68
  69             ((ScrollbarStyle)instance.viewStyle).TrackColor = color;
  70             instance.UpdateTrackColor(color);
  71         },
  72         defaultValueCreator: (bindable) =>
  73         {
  74             return ((ScrollbarStyle)((Scrollbar)bindable).viewStyle)?.TrackColor;
  75         });
  76
  77         /// <summary>Bindable property of ThumbColor</summary>
  78         [EditorBrowsable(EditorBrowsableState.Never)]
  79         public static readonly BindableProperty ThumbColorProperty = BindableProperty.Create(nameof(ThumbColor), typeof(Color), typeof(Scrollbar), null, propertyChanged: (bindable, oldValue, newValue) =>
  80         {
  81             var instance = ((Scrollbar)bindable);
  82             var color = (Color)newValue;
  83
  84             ((ScrollbarStyle)instance.viewStyle).ThumbColor = color;
  85             instance.UpdateThumbColor(color);
  86         },
  87         defaultValueCreator: (bindable) =>
  88         {
  89             return ((ScrollbarStyle)((Scrollbar)bindable).viewStyle)?.ThumbColor;
  90         });
  91
  92         /// <summary>Bindable property of TrackPadding</summary>
  93         [EditorBrowsable(EditorBrowsableState.Never)]
  94         public static readonly BindableProperty TrackPaddingProperty = BindableProperty.Create(nameof(TrackPadding), typeof(Extents), typeof(Scrollbar), null, propertyChanged: (bindable, oldValue, newValue) =>
  95         {
  96             var instance = ((Scrollbar)bindable);
  97             var trackPadding = (Extents)newValue;
  98
  99             ((ScrollbarStyle)instance.viewStyle).TrackPadding = trackPadding;
 100             instance.UpdateTrackPadding(trackPadding);
 101         },
 102         defaultValueCreator: (bindable) =>
 103         {
 104             return ((ScrollbarStyle)((Scrollbar)bindable).viewStyle)?.TrackPadding;
 105         });
 106
 107         private static readonly string TrackVisualName = "Track";
 108         private static readonly string ThumbVisualName = "Thumb";
 109         private ColorVisual trackVisual;
 110         private ColorVisual thumbVisual;
 111         private Animation thumbPositionAnimation;
 112         private Animation thumbSizeAnimation;
 113         private Calculator calculator;
 114
 115         #endregion Fields
 116
 117
 118         #region Constructors
 119
 120         /// <summary>
 121         /// Create an empty Scrollbar.
 122         /// </summary>
 123         public Scrollbar() : base(new ScrollbarStyle())
 124         {
 125         }
 126
 127         /// <summary>
 128         /// Create a Scrollbar and initialize with properties.
 129         /// </summary>
 130         /// <param name="contentLength">The total length of the content.</param>
 131         /// <param name="viewSize">The size of View that contains the content to scroll.</param>
 132         /// <param name="currentPosition">The start position of the View in content length. This is the View's top position if the scroller is vertical, otherwise, View's left position.</param>
 133         /// <param name="isHorizontal">Whether the direction of scrolling is horizontal or not. It is vertical if the value is false.</param>
 134         [EditorBrowsable(EditorBrowsableState.Never)]
 135         public Scrollbar(float contentLength, Size viewSize, float currentPosition, bool isHorizontal = false) : base(new ScrollbarStyle())
 136         {
 137             Initialize(contentLength, viewSize, currentPosition, isHorizontal);
 138         }
 139
 140         /// <summary>
 141         /// Create an empty Scrollbar with a ScrollbarStyle instance to set style properties.
 142         /// </summary>
 143         [EditorBrowsable(EditorBrowsableState.Never)]
 144         public Scrollbar(ScrollbarStyle style) : base(style)
 145         {
 146         }
 147
 148         /// <summary>
 149         /// Static constructor to initialize bindable properties when loading.
 150         /// </summary>
 151         static Scrollbar()
 152         {
 153         }
 154
 155         #endregion Constructors
 156
 157
 158         #region Properties
 159
 160         /// <summary>
 161         /// The thickness of the track.
 162         /// </summary>
 163         [EditorBrowsable(EditorBrowsableState.Never)]
 164         public float TrackThickness
 165         {
 166             get => (float)GetValue(TrackThicknessProperty);
 167             set => SetValue(TrackThicknessProperty, value);
 168         }
 169
 170         /// <summary>
 171         /// The thickness of the thumb.
 172         /// </summary>
 173         [EditorBrowsable(EditorBrowsableState.Never)]
 174         public float ThumbThickness
 175         {
 176             get => (float)GetValue(ThumbThicknessProperty);
 177             set => SetValue(ThumbThicknessProperty, value);
 178         }
 179
 180         /// <summary>
 181         /// The color of the track part.
 182         /// </summary>
 183         [EditorBrowsable(EditorBrowsableState.Never)]
 184         public Color TrackColor
 185         {
 186             get => (Color)GetValue(TrackColorProperty);
 187             set => SetValue(TrackColorProperty, value);
 188         }
 189
 190         /// <summary>
 191         /// The color of the thumb part.
 192         /// </summary>
 193         [EditorBrowsable(EditorBrowsableState.Never)]
 194         public Color ThumbColor
 195         {
 196             get => (Color)GetValue(ThumbColorProperty);
 197             set => SetValue(ThumbColorProperty, value);
 198         }
 199
 200         /// <summary>
 201         /// The padding value of the track.
 202         /// </summary>
 203         [EditorBrowsable(EditorBrowsableState.Never)]
 204         public Extents TrackPadding
 205         {
 206             get => (Extents)GetValue(TrackPaddingProperty);
 207             set => SetValue(TrackPaddingProperty, value);
 208         }
 209
 210         #endregion Properties
 211
 212
 213         #region Methods
 214
 215         /// <inheritdoc/>
 216         [EditorBrowsable(EditorBrowsableState.Never)]
 217         public override void Initialize(float contentLength, Size viewSize, float currentPosition, bool isHorizontal = false)
 218         {
 219             if (isHorizontal)
 220             {
 221                 calculator = new HorizontalCalculator(contentLength > 0.0f ? contentLength : 0.0f, viewSize.Width);
 222             }
 223             else
 224             {
 225                 calculator = new VerticalCalculator(contentLength > 0.0f ? contentLength : 0.0f, viewSize.Height);
 226             }
 227
 228             Size = viewSize;
 229
 230             thumbPositionAnimation?.Stop();
 231             thumbPositionAnimation = null;
 232
 233             thumbSizeAnimation?.Stop();
 234             thumbSizeAnimation = null;
 235
 236             CreateTrackVisual();
 237             CreateThumbVisual(currentPosition);
 238
 239             AddVisual(TrackVisualName, trackVisual);
 240             AddVisual(ThumbVisualName, thumbVisual);
 241         }
 242
 243         /// <inheritdoc/>
 244         /// <remarks>Please note that, for now, only alpha functions created with BuiltinFunctions are valid when animating. Otherwise, it will be treated as a linear alpha function. </remarks>
 245         [EditorBrowsable(EditorBrowsableState.Never)]
 246         public override void Update(float contentLength, float position, uint durationMs = 0, AlphaFunction alphaFunction = null)
 247         {
 248             if (calculator == null)
 249             {
 250                 return;
 251             }
 252
 253             calculator.Update(contentLength > 0.0f ? contentLength : 0.0f);
 254
 255             thumbVisual.Size = calculator.CalculateThumbSize(ThumbThickness, trackVisual.Size);
 256             thumbVisual.Position = calculator.CalculateThumbScrollPosition(position, trackVisual.Size, thumbVisual.Position, TrackPadding);
 257             thumbVisual.Opacity = calculator.CalculateThumbVisibility() ? 1.0f : 0.0f;
 258
 259             if (durationMs == 0)
 260             {
 261                 thumbVisual.UpdateVisual(true);
 262
 263                 return;
 264             }
 265
 266             // TODO Support non built-in alpha function for visual trainsition in DALi.
 267             AlphaFunction.BuiltinFunctions builtinAlphaFunction = alphaFunction?.GetBuiltinFunction() ?? AlphaFunction.BuiltinFunctions.Default;
 268
 269             thumbPositionAnimation?.Stop();
 270             thumbPositionAnimation = AnimateVisual(thumbVisual, "position", thumbVisual.Position, 0, (int)durationMs, builtinAlphaFunction);
 271             thumbPositionAnimation.Play();
 272
 273             thumbSizeAnimation?.Stop();
 274             thumbSizeAnimation = AnimateVisual(thumbVisual, "size", thumbVisual.Size, 0, (int)durationMs, builtinAlphaFunction);
 275             thumbSizeAnimation.Play();
 276         }
 277
 278         /// <inheritdoc/>
 279         /// <remarks>Please note that, for now, only alpha functions created with BuiltinFunctions are valid when animating. Otherwise, it will be treated as a linear alpha function. </remarks>
 280         [EditorBrowsable(EditorBrowsableState.Never)]
 281         public override void ScrollTo(float position, uint durationMs = 0, AlphaFunction alphaFunction = null)
 282         {
 283             if (thumbVisual == null)
 284             {
 285                 return;
 286             }
 287
 288             thumbVisual.Position = calculator.CalculateThumbScrollPosition(position, trackVisual.Size, thumbVisual.Position, TrackPadding);
 289
 290             if (durationMs == 0)
 291             {
 292                 thumbVisual.UpdateVisual(true);
 293
 294                 return;
 295             }
 296
 297             // TODO Support non built-in alpha function for visual trainsition in DALi.
 298             AlphaFunction.BuiltinFunctions builtinAlphaFunction = alphaFunction?.GetBuiltinFunction() ?? AlphaFunction.BuiltinFunctions.Default;
 299
 300             thumbPositionAnimation?.Stop();
 301             thumbPositionAnimation = AnimateVisual(thumbVisual, "position", thumbVisual.Position, 0, (int)durationMs, builtinAlphaFunction);
 302             thumbPositionAnimation.Play();
 303         }
 304
 305         /// <inheritdoc/>
 306         [EditorBrowsable(EditorBrowsableState.Never)]
 307         protected override ViewStyle GetViewStyle()
 308         {
 309             return new ScrollbarStyle();
 310         }
 311
 312         /// <summary>
 313         /// Create a track visual.
 314         /// </summary>
 315         [EditorBrowsable(EditorBrowsableState.Never)]
 316         protected virtual void CreateTrackVisual()
 317         {
 318             trackVisual = new ColorVisual
 319             {
 320                 SuppressUpdateVisual = true,
 321                 Color = Color.Black,
 322                 SizePolicy = VisualTransformPolicyType.Absolute,
 323                 Origin = calculator.CalculatorTrackAlign(),
 324                 AnchorPoint = calculator.CalculatorTrackAlign(),
 325                 Size = calculator.CalculateTrackSize(TrackThickness, TrackPadding),
 326                 Position = calculator.CalculateTrackPosition(TrackPadding),
 327             };
 328         }
 329
 330         /// <summary>
 331         /// Create a thumb visual.
 332         /// </summary>
 333         [EditorBrowsable(EditorBrowsableState.Never)]
 334         protected virtual void CreateThumbVisual(float currentPosition)
 335         {
 336             Size thumbSize = calculator.CalculateThumbSize(ThumbThickness, trackVisual.Size);
 337
 338             thumbVisual = new ColorVisual
 339             {
 340                 SuppressUpdateVisual = true,
 341                 MixColor = ThumbColor,
 342                 SizePolicy = VisualTransformPolicyType.Absolute,
 343                 Origin = calculator.CalculatorThumbAlign(),
 344                 AnchorPoint = calculator.CalculatorThumbAlign(),
 345                 Size = thumbSize,
 346                 Position = calculator.CalculateThumbPosition(currentPosition, trackVisual.Size, thumbSize, TrackPadding),
 347                 Opacity = (calculator.CalculateThumbVisibility() ? 1.0f : 0.0f),
 348             };
 349         }
 350
 351         /// <summary>
 352         /// Update TrackThickness property of the scrollbar.
 353         /// </summary>
 354         /// <param name="thickness">The width of the track.</param>
 355         [EditorBrowsable(EditorBrowsableState.Never)]
 356         protected virtual void UpdateTrackThickness(float thickness)
 357         {
 358             if (trackVisual == null)
 359             {
 360                 return;
 361             }
 362
 363             trackVisual.Size = calculator.CalculateTrackSize(thickness, TrackPadding);
 364             trackVisual.UpdateVisual(true);
 365         }
 366
 367         /// <summary>
 368         /// Update ThumbThickness property of the scrollbar.
 369         /// </summary>
 370         /// <param name="thickness">The width of the track.</param>
 371         [EditorBrowsable(EditorBrowsableState.Never)]
 372         protected virtual void UpdateThumbThickness(float thickness)
 373         {
 374             if (thumbVisual == null)
 375             {
 376                 return;
 377             }
 378
 379             thumbVisual.Size = calculator.CalculateThumbSize(thickness, trackVisual.Size);
 380             thumbVisual.UpdateVisual(true);
 381         }
 382
 383         /// <summary>
 384         /// Update TrackColor property of the scrollbar.
 385         /// </summary>
 386         /// <param name="color">The color of the track.</param>
 387         [EditorBrowsable(EditorBrowsableState.Never)]
 388         protected virtual void UpdateTrackColor(Color color)
 389         {
 390             if (trackVisual == null)
 391             {
 392                 return;
 393             }
 394
 395             trackVisual.MixColor = color;
 396             trackVisual.UpdateVisual(true);
 397         }
 398
 399         /// <summary>
 400         /// Update ThumbColor property of the scrollbar.
 401         /// </summary>
 402         /// <param name="color">The color of the thumb.</param>
 403         [EditorBrowsable(EditorBrowsableState.Never)]
 404         protected virtual void UpdateThumbColor(Color color)
 405         {
 406             if (thumbVisual == null)
 407             {
 408                 return;
 409             }
 410
 411             thumbVisual.MixColor = color;
 412             thumbVisual.UpdateVisual(true);
 413         }
 414
 415         /// <summary>
 416         /// Update TrackPadding property of the scrollbar.
 417         /// </summary>
 418         /// <param name="trackPadding">The padding of the track.</param>
 419         protected virtual void UpdateTrackPadding(Extents trackPadding)
 420         {
 421             if (trackVisual == null || thumbVisual == null)
 422             {
 423                 return;
 424             }
 425
 426             trackVisual.Size = calculator.CalculateTrackSize(TrackThickness, trackPadding);
 427             trackVisual.Position = calculator.CalculateTrackPosition(trackPadding);
 428             thumbVisual.Size = calculator.CalculateThumbSize(ThumbThickness, trackVisual.Size);
 429             thumbVisual.Position = calculator.CalculateThumbPaddingPosition(trackVisual.Size, thumbVisual.Size, thumbVisual.Position, trackPadding);
 430
 431             trackVisual.UpdateVisual(true);
 432             thumbVisual.UpdateVisual(true);
 433         }
 434
 435         #endregion Methods
 436
 437
 438         #region Classes
 439
 440         private abstract class Calculator
 441         {
 442             protected float contentLength;
 443             protected float visibleLength;
 444
 445             public Calculator(float contentLength, float visibleLength)
 446             {
 447                 this.contentLength = contentLength;
 448                 this.visibleLength = visibleLength;
 449             }
 450
 451             public void Update(float contentLength)
 452             {
 453                 this.contentLength = contentLength;
 454             }
 455
 456             public bool CalculateThumbVisibility()
 457             {
 458                 return contentLength > visibleLength;
 459             }
 460
 461             public abstract Visual.AlignType CalculatorTrackAlign();
 462             public abstract Visual.AlignType CalculatorThumbAlign();
 463             public abstract Size CalculateTrackSize(float thickness, Extents trackPadding);
 464             public abstract Vector2 CalculateTrackPosition(Extents trackPadding);
 465             public abstract Size CalculateThumbSize(float thickness, Size trackSize);
 466             public abstract Vector2 CalculateThumbPosition(float position, Size trackSize, Size thumbSize, Extents trackPadding);
 467             public abstract Vector2 CalculateThumbPaddingPosition(Size trackSize, Size thumbSize, Vector2 thumbCurrentPosition, Extents trackPadding);
 468             public abstract Vector2 CalculateThumbScrollPosition(float position, Size trackSize, Vector2 thumbCurrentPosition, Extents trackPadding);
 469         }
 470
 471         private class HorizontalCalculator : Calculator
 472         {
 473             public HorizontalCalculator(float contentLength, float visibleLength) : base(contentLength, visibleLength)
 474             {
 475             }
 476
 477             public override Visual.AlignType CalculatorTrackAlign()
 478             {
 479                 return Visual.AlignType.BottomCenter;
 480             }
 481
 482             public override Visual.AlignType CalculatorThumbAlign()
 483             {
 484                 return Visual.AlignType.BottomBegin;
 485             }
 486
 487             public override Size CalculateTrackSize(float thickness, Extents trackPadding)
 488             {
 489                 return new Size(visibleLength - trackPadding.Start - trackPadding.End, thickness);
 490             }
 491
 492             public override Vector2 CalculateTrackPosition(Extents trackPadding)
 493             {
 494                 return new Vector2(0, -trackPadding.Bottom);
 495             }
 496
 497             public override Size CalculateThumbSize(float thickness, Size trackSize)
 498             {
 499                 return new Size(trackSize.Width * visibleLength / contentLength, thickness);
 500             }
 501
 502             public override Vector2 CalculateThumbPosition(float position, Size trackSize, Size thumbSize, Extents trackPadding)
 503             {
 504                 float padding = ((trackSize.Height - thumbSize.Height) / 2.0f) + trackPadding.Bottom;
 505                 float pos = Math.Min(Math.Max(position, 0.0f), contentLength - visibleLength);
 506                 return new Vector2(trackPadding.Start + trackSize.Width * pos / contentLength, -padding);
 507             }
 508
 509             public override Vector2 CalculateThumbPaddingPosition(Size trackSize, Size thumbSize, Vector2 thumbCurrentPosition, Extents trackPadding)
 510             {
 511                 float padding = ((trackSize.Height - thumbSize.Height) / 2.0f) + trackPadding.Bottom;
 512                 return new Vector2(thumbCurrentPosition.X, -padding);
 513             }
 514
 515             public override Vector2 CalculateThumbScrollPosition(float position, Size trackSize, Vector2 thumbCurrentPosition, Extents trackPadding)
 516             {
 517                 float pos = Math.Min(Math.Max(position, 0.0f), contentLength - visibleLength);
 518                 return new Vector2(trackPadding.Start + trackSize.Width * pos / contentLength, thumbCurrentPosition.Y);
 519             }
 520         }
 521
 522         private class VerticalCalculator : Calculator
 523         {
 524             public VerticalCalculator(float contentLength, float visibleLength) : base(contentLength, visibleLength)
 525             {
 526             }
 527
 528             public override Visual.AlignType CalculatorTrackAlign()
 529             {
 530                 return Visual.AlignType.CenterEnd;
 531             }
 532
 533             public override Visual.AlignType CalculatorThumbAlign()
 534             {
 535                 return Visual.AlignType.TopEnd;
 536             }
 537
 538             public override Size CalculateTrackSize(float thickness, Extents trackPadding)
 539             {
 540                 return new Size(thickness, visibleLength - trackPadding.Top - trackPadding.Bottom);
 541             }
 542
 543             public override Vector2 CalculateTrackPosition(Extents trackPadding)
 544             {
 545                 return new Vector2(-trackPadding.End, 0);
 546             }
 547
 548             public override Size CalculateThumbSize(float thickness, Size trackSize)
 549             {
 550                 return new Size(thickness, trackSize.Height * visibleLength / contentLength);
 551             }
 552
 553             public override Vector2 CalculateThumbPosition(float position, Size trackSize, Size thumbSize, Extents trackPadding)
 554             {
 555                 float padding = ((trackSize.Width - thumbSize.Width) / 2.0f) + trackPadding.End;
 556                 float pos = Math.Min(Math.Max(position, 0.0f), contentLength - visibleLength);
 557                 return new Vector2(-padding, trackPadding.Top + trackSize.Height * pos / contentLength);
 558             }
 559
 560             public override Vector2 CalculateThumbPaddingPosition(Size trackSize, Size thumbSize, Vector2 thumbCurrentPosition, Extents trackPadding)
 561             {
 562                 float padding = ((trackSize.Width - thumbSize.Width) / 2.0f) + trackPadding.End;
 563                 return new Vector2(-padding, thumbCurrentPosition.Y);
 564             }
 565
 566             public override Vector2 CalculateThumbScrollPosition(float position, Size trackSize, Vector2 thumbPosition, Extents trackPadding)
 567             {
 568                 float pos = Math.Min(Math.Max(position, 0.0f), contentLength - visibleLength);
 569                 return new Vector2(thumbPosition.X, trackPadding.Top + trackSize.Height * pos / contentLength);
 570             }
 571         }
 572
 573         #endregion Classes
 574     }
 575 }