Add support for images in dialogue windows (#19)

- Extend editor nodes with custom DialogueContent data type that holds either image or text
- Extend the dialogue importer to correctly process the new content into updated RuntimeDialogue content
- Update SpeechBubble to be able to display either text or image
- Add a custom property drawer for the DialogueContent to allow easy switching in graph authoring

Co-authored-by: Michal Pikulski <michal@foolhardyhorizons.com>
Reviewed-on: #19

Assets/Scripts/Dialogue/SpeechBubble.cs

@@ -2,6 +2,7 @@
 using System.Collections;
 using TMPro;
 using UnityEngine;
+using UnityEngine.UI;
 
 namespace Dialogue
 {
@@ -18,6 +19,7 @@ namespace Dialogue
     public class SpeechBubble : MonoBehaviour
     {
         [SerializeField] private TextMeshProUGUI textDisplay;
+        [SerializeField] private Image imageDisplay; // New field for displaying images
         [SerializeField] private TextDisplayMode displayMode = TextDisplayMode.Typewriter;
         [SerializeField] private float typewriterSpeed = 0.05f; // Time between characters in seconds
         [SerializeField] private AudioSource typingSoundSource;
@@ -29,11 +31,18 @@ namespace Dialogue
         private Coroutine typewriterCoroutine;
         private Coroutine promptUpdateCoroutine;
         private string currentFullText = string.Empty;
+        private Sprite currentImage = null;
         private bool isVisible = false;
+        private DialogueContentType currentContentType = DialogueContentType.Text;
 
         private void Awake()
         {
-
+            // Ensure we have both components
+            if (textDisplay == null)
+                Debug.LogError("SpeechBubble: TextMeshProUGUI component is not assigned!");
+                
+            if (imageDisplay == null)
+                Debug.LogError("SpeechBubble: Image component is not assigned!");
         }
 
         /// <summary>
@@ -92,6 +101,7 @@ namespace Dialogue
             }
 
             currentFullText = text;
+            currentContentType = DialogueContentType.Text;
 
             // Stop any existing typewriter effect
             if (typewriterCoroutine != null)
@@ -100,6 +110,13 @@ namespace Dialogue
                 typewriterCoroutine = null;
             }
 
+            // Activate text display, deactivate image display
+            textDisplay.gameObject.SetActive(true);
+            if (imageDisplay != null)
+            {
+                imageDisplay.gameObject.SetActive(false);
+            }
+
             // Display text based on the selected mode
             if (displayMode == TextDisplayMode.Instant)
             {
@@ -259,5 +276,117 @@ namespace Dialogue
             
             typewriterCoroutine = null;
         }
+
+        /// <summary>
+        /// Set the image to display in the speech bubble
+        /// </summary>
+        /// <param name="sprite">Sprite to display</param>
+        public void SetImage(Sprite sprite)
+        {
+            if (imageDisplay == null)
+            {
+                Debug.LogError("SpeechBubble: Image component is not assigned!");
+                return;
+            }
+
+            currentImage = sprite;
+            currentContentType = DialogueContentType.Image;
+
+            // Activate image display, set the sprite
+            imageDisplay.gameObject.SetActive(true);
+            imageDisplay.sprite = sprite;
+
+            // Deactivate text display
+            if (textDisplay != null)
+            {
+                textDisplay.gameObject.SetActive(false);
+            }
+
+            // Make sure the bubble is visible when setting image
+            if (!isVisible)
+                Show();
+        }
+
+        /// <summary>
+        /// Clear the displayed image
+        /// </summary>
+        public void ClearImage()
+        {
+            SetImage(null);
+        }
+
+        /// <summary>
+        /// Set the content of the speech bubble (text or image)
+        /// </summary>
+        /// <param name="text">Text content</param>
+        /// <param name="image">Image content</param>
+        public void SetContent(string text, Sprite image)
+        {
+            if (!string.IsNullOrEmpty(text))
+            {
+                currentContentType = DialogueContentType.Text;
+                SetText(text);
+            }
+            else if (image != null)
+            {
+                currentContentType = DialogueContentType.Image;
+                SetImage(image);
+            }
+        }
+
+        /// <summary>
+        /// Get the current content type of the speech bubble
+        /// </summary>
+        /// <returns>Current content type</returns>
+        public DialogueContentType GetCurrentContentType()
+        {
+            return currentContentType;
+        }
+
+        /// <summary>
+        /// Display dialogue content (text or image)
+        /// </summary>
+        /// <param name="content">The dialogue content to display</param>
+        /// <param name="hasMoreDialogue">Whether there are more dialogue content items available</param>
+        public void DisplayDialogueContent(DialogueContent content, bool hasMoreDialogue)
+        {
+            // Cancel any existing prompt update
+            if (promptUpdateCoroutine != null)
+            {
+                StopCoroutine(promptUpdateCoroutine);
+                promptUpdateCoroutine = null;
+            }
+            
+            if (content == null)
+            {
+                UpdatePromptVisibility(hasMoreDialogue);
+                return;
+            }
+            
+            // Display the content based on its type
+            currentContentType = content.ContentType;
+            
+            if (content.ContentType == DialogueContentType.Text)
+            {
+                // Show text display, hide image display
+                textDisplay.gameObject.SetActive(true);
+                if (imageDisplay != null) imageDisplay.gameObject.SetActive(false);
+                
+                // Display the text
+                DisplayDialogueLine(content.Text, hasMoreDialogue);
+            }
+            else // Image content
+            {
+                // Hide text display, show image display
+                textDisplay.gameObject.SetActive(false);
+                if (imageDisplay != null) imageDisplay.gameObject.SetActive(true);
+                
+                // Set the image
+                SetImage(content.Image);
+                
+                // After a delay, update the prompt visibility
+                promptUpdateCoroutine = StartCoroutine(UpdatePromptAfterDelay(hasMoreDialogue));
+            }
+        }
     }
 }