// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
// Standard Library
using System;
// Unity
using UnityEditor;
using UnityEngine;
// GameKit
using AWS.GameKit.Editor.FileStructure;
namespace AWS.GameKit.Editor.GUILayoutExtensions
{
/// <summary>
/// A GUI element which displays a link followed by an external icon, optionally prepended with a label.
/// </summary>
public class LinkWidget : IDrawable
{
// Data
private readonly string _prependedText;
private readonly float _spaceAfterPrependedText;
private readonly string _linkLabel;
private readonly Options _options;
private readonly Action _onClick;
// Styles
private GUIStyle _linkTextStyle;
private GUIStyle _prependedTextStyle;
private GUIStyle _iconStyle;
private GUIStyle _iconStyleWithoutOffset;
/// <summary>
/// Create a new LinkWidget.
/// </summary>
/// <param name="linkLabel">The link text to display.</param>
/// <param name="onClick">The action to execute when clicking on the link.</param>
/// <param name="options">Styling options to apply.</param>
public LinkWidget(string linkLabel, Action onClick, Options options = null)
{
_linkLabel = linkLabel;
_onClick = onClick;
_options = options ?? new Options();
}
/// <summary>
/// Create a new LinkWidget with a label placed before it.
/// </summary>
/// <param name="prependedText">The text to place directly before the <c>linkLabel</c>.</param>
/// <param name="linkLabel">The link text to display.</param>
/// <param name="onClick">The action to execute when clicking on the link.</param>
/// <param name="options">Styling options to apply.</param>
/// <param name="spaceAfterPrependedText">The amount of space to place between the <c>prependedText</c> and <c>linkLabel</c>.</param>
public LinkWidget(string prependedText, string linkLabel, Action onClick, Options options = null, float spaceAfterPrependedText = 0f)
: this(linkLabel, onClick, options)
{
_prependedText = prependedText;
_spaceAfterPrependedText = spaceAfterPrependedText;
}
/// <summary>
/// Create a new LinkWidget.
/// </summary>
/// <param name="linkLabel">The text to display in place of the URL.</param>
/// <param name="url">The link that clicking the label text will route to.</param>
/// <param name="options">Styling options to apply.</param>
public LinkWidget(string linkLabel, string url, Options options = null)
: this(linkLabel, () => Application.OpenURL(url), options)
{
}
/// <summary>
/// Create a new LinkWidget with a label placed before it.
/// </summary>
/// <param name="prependedText">The text to place directly before the <c>linkLabel</c>.</param>
/// <param name="linkLabel">The text to display in place of the URL.</param>
/// <param name="url">The link that clicking the label text will route to.</param>
/// <param name="options">Styling options to apply.</param>
/// <param name="spaceAfterPrependedText">The amount of space to place between the <c>prependedText</c> and <c>linkLabel</c>.</param>
public LinkWidget(string prependedText, string linkLabel, string url, Options options = null, float spaceAfterPrependedText = 0f)
: this(linkLabel, url, options)
{
_prependedText = prependedText;
_spaceAfterPrependedText = spaceAfterPrependedText;
}
/// <summary>
/// Styling options for the LinkWidget class.
/// </summary>
public class Options
{
/// <summary>
/// A GUIStyle to apply to the horizontal layout section which contains the entire link widget (the prepended text, link label, and icon).
/// </summary>
public GUIStyle OverallStyle = GUIStyle.none;
/// <summary>
/// Whether to enable/disable word wrapping for the <c>linkLabel</c> parameter's text.
/// </summary>
public bool ShouldWordWrapLinkLabel = true;
/// <summary>
/// Number of pixels to shift the entire link widget (prepended text, link label, and icon).
/// </summary>
public Vector2 ContentOffset = Vector2.zero;
/// <summary>
/// Alignment of the entire link widget (prepended text, link label, and icon).
/// </summary>
public Alignment Alignment = Alignment.Left;
/// <summary>
/// The tooltip to show when the mouse is hovering over the link. By default no tooltip is shown.
/// </summary>
public string Tooltip = string.Empty;
/// <summary>
/// Whether to draw the external icon after the link label.
/// </summary>
public bool ShouldDrawExternalIcon = true;
}
/// <summary>
/// The alignment of the entire link widget (prepended text, link label, and icon).
/// </summary>
public enum Alignment
{
/// <summary>
/// The LinkWidget is aligned to the left, by placing a GUILayout.FlexibleSpace() at the end of it's horizontal layout group.
/// </summary>
Left,
/// <summary>
/// The LinkWidget is aligned to the right by placing a GUILayout.FlexibleSpace() at the beginning of it's horizontal layout group.
/// </summary>
Right,
/// <summary>
/// The LinkWidget is placed in the default manner for a horizontal layout group.
/// It does not use a GUILayout.FlexibleSpace() to position itself.
/// </summary>
None,
}
/// <summary>
/// Draw the LinkWidget.
/// </summary>
public void OnGUI()
{
SetGUIStyles();
using (new EditorGUILayout.HorizontalScope(_options.OverallStyle))
{
if (_options.Alignment == Alignment.Right)
{
GUILayout.FlexibleSpace();
}
DrawPrependedText();
DrawLinkWithExternalIcon();
if (_options.Alignment == Alignment.Left)
{
GUILayout.FlexibleSpace();
}
}
}
// Avoid a null-reference exception by creating the GUIStyles during OnGUI instead of the constructor.
// The exception happens because EditorStyles (ex: EditorStyles.label) are null until the first frame of the GUI.
private void SetGUIStyles()
{
_linkTextStyle = new GUIStyle(LinkWidgetStyles.LinkLabelStyle)
{
wordWrap = _options.ShouldWordWrapLinkLabel
};
Vector2 totalContentOffset = _options.ContentOffset + LinkWidgetStyles.BaselineContentOffset;
_linkTextStyle = CommonGUIStyles.AddContentOffset(_linkTextStyle, totalContentOffset);
_linkTextStyle.fontSize = _options.OverallStyle.fontSize;
_prependedTextStyle = CommonGUIStyles.AddContentOffset(LinkWidgetStyles.PrependedTextStyle, totalContentOffset);
_iconStyleWithoutOffset = _linkTextStyle.fontSize == 10
? LinkWidgetStyles.IconStyleSmall
: LinkWidgetStyles.IconStyleNormal;
_iconStyle = CommonGUIStyles.AddContentOffset(_iconStyleWithoutOffset, totalContentOffset);
}
private void DrawPrependedText()
{
if (string.IsNullOrEmpty(_prependedText))
{
return;
}
EditorGUILayout.LabelField(_prependedText, _prependedTextStyle);
if (_spaceAfterPrependedText != 0)
{
// We only create this Space() element if non-zero, because Space(0) actually creates a non zero-width space.
EditorGUILayout.Space(_spaceAfterPrependedText);
}
}
/// <summary>
/// Draws a button, that is styled to look like a hyperlink, followed by an external link Icon.
/// </summary>
private void DrawLinkWithExternalIcon()
{
GUILayout.Label(_linkLabel, _linkTextStyle);
Rect buttonRect = GUILayoutUtility.GetLastRect();
buttonRect.x += _options.ContentOffset.x;
buttonRect.y += _options.ContentOffset.y;
buttonRect.width = _linkTextStyle.CalcSize(new GUIContent(_linkLabel)).x;
if (_options.ShouldDrawExternalIcon)
{
// Draw icon
GUILayout.Box(EditorResources.Textures.SettingsWindow.ExternalLinkIcon.Get(), _iconStyle);
buttonRect.width += GUILayoutUtility.GetLastRect().width + _iconStyleWithoutOffset.fixedWidth / 3f;
}
// Create a button with no text but spans the length of both the text and the icon (if drawn)
GUIContent buttonContent = new GUIContent(string.Empty, _options.Tooltip);
if (GUI.Button(buttonRect, buttonContent, GUIStyle.none))
{
_onClick();
}
// Change mouse cursor to a "pointer" when hovering over the button
EditorGUIUtility.AddCursorRect(buttonRect, MouseCursor.Link);
}
/// <summary>
/// Subclass containing all specific styles for the LinkWidget.
/// </summary>
private static class LinkWidgetStyles
{
// The link widget is 2 pixels higher than other text on it's same line.
// This offset brings it back down to where it should be.
public static readonly Vector2 BaselineContentOffset = new Vector2(0, 2);
private static readonly GUIStyleState LinkLabelStyleState = new GUIStyleState()
{
background = EditorStyles.label.normal.background,
scaledBackgrounds = EditorStyles.label.normal.scaledBackgrounds,
textColor = EditorStyles.linkLabel.normal.textColor
};
public static readonly GUIStyle LinkLabelStyle = new GUIStyle(EditorStyles.label)
{
active = EditorStyles.linkLabel.active,
hover = EditorStyles.linkLabel.hover,
normal = LinkLabelStyleState,
stretchWidth = false,
};
public static readonly GUIStyle PrependedTextStyle = new GUIStyle(EditorStyles.label)
{
wordWrap = true
};
public static readonly GUIStyle IconStyleNormal = new GUIStyle()
{
contentOffset = new Vector2(2, 3),
fixedWidth = 14,
fixedHeight = 14
};
public static readonly GUIStyle IconStyleSmall = new GUIStyle()
{
contentOffset = new Vector2(0, 2),
fixedWidth = 10,
fixedHeight = 10
};
}
}
}