Improve question review and image handling

api/QuestionsApi/Models/QuestionRequests.cs

@@ -9,6 +9,7 @@ public class QuestionSearchRequest
     public int? DifficultyMax { get; set; }
     public int Limit { get; set; } = 40;
     public bool SupportsChoicePools { get; set; }
+    public bool RequireMedia { get; set; }
     public List<string> ExcludeExternalIds { get; set; } = [];
 }
 

api/QuestionsApi/Services/QuestionStore.cs

@@ -37,6 +37,8 @@ public class QuestionStore
             filters.Add(builder.Gte(q => q.Difficulty, req.DifficultyMin.Value));
         if (req.DifficultyMax is not null)
             filters.Add(builder.Lte(q => q.Difficulty, req.DifficultyMax.Value));
+        if (req.RequireMedia)
+            filters.Add(builder.Exists("Media.0", true));
         var excludedIds = req.ExcludeExternalIds
             .Where(id => !string.IsNullOrWhiteSpace(id))
             .Select(id => id.Trim())

scripts/autoload/question_bank_service.gd

@@ -7,6 +7,7 @@ const DEFAULT_QUESTION_API_BASE_URL := "https://s3q.ranaze.com/api/questions"
 const DEFAULT_RATINGS_API_URL := "https://s3q.ranaze.com/api/ratings/me"
 const DEFAULT_QUESTION_REPORTS_API_URL := "https://s3q.ranaze.com/api/question-reports"
 const RETRY_DELAYS := [2, 5, 10, 20, 30]
+const IMAGE_QUESTION_SEARCH_LIMIT := 200
 const ATTEMPT_QUEUE_PATH := "user://pending_question_attempts.json"
 
 signal questions_changed
@@ -44,6 +45,8 @@ var attempt_queue: Array = []
 var active_attempt_index := -1
 var attempt_request_active := false
 var pending_excluded_question_ids: Array = []
+var pending_require_media := false
+var image_question_search_attempts := 0
 
 func _ready() -> void:
 	questions_api_url = EndpointConfig.resolve(
@@ -93,13 +96,15 @@ func _ready() -> void:
 	_process_attempt_queue()
 
 
-func load_questions_from_api(reset_retry: bool = true, excluded_question_ids: Array = []) -> void:
+func load_questions_from_api(reset_retry: bool = true, excluded_question_ids: Array = [], require_media: bool = false) -> void:
 	if AuthState.access_token.is_empty():
 		_set_load_error("Login required before loading questions.", false)
 		return
 
 	if reset_retry:
 		pending_excluded_question_ids = excluded_question_ids.duplicate()
+		pending_require_media = require_media
+		image_question_search_attempts = 0
 		retry_attempt = 0
 		next_retry_seconds = 0
 		retry_timer.stop()
@@ -120,6 +125,7 @@ func load_questions_from_api(reset_retry: bool = true, excluded_question_ids: Ar
 	var payload := {
 		"limit": 1,
 		"supportsChoicePools": true,
+		"requireMedia": pending_require_media,
 		"excludeExternalIds": pending_excluded_question_ids
 	}
 	var err := request.request(questions_api_url, headers, HTTPClient.METHOD_POST, JSON.stringify(payload))
@@ -147,6 +153,17 @@ func _on_api_questions_loaded(result: int, response_code: int, _headers: PackedS
 	if api_questions.is_empty():
 		_set_load_error("Questions API returned no usable questions.")
 		return
+	if pending_require_media and not _contains_question_with_media(api_questions):
+		for question in api_questions:
+			var question_id := str(question.get("id", ""))
+			if question_id != "" and not pending_excluded_question_ids.has(question_id):
+				pending_excluded_question_ids.append(question_id)
+		image_question_search_attempts += api_questions.size()
+		if image_question_search_attempts >= IMAGE_QUESTION_SEARCH_LIMIT:
+			_set_load_error("No question with an image was found.", false)
+			return
+		call_deferred("load_questions_from_api", false, pending_excluded_question_ids, true)
+		return
 
 	questions = api_questions
 	last_error = ""
@@ -168,6 +185,18 @@ func load_next_random_question(excluded_question_ids: Array) -> void:
 	load_questions_from_api(true, excluded_question_ids)
 
 
+func load_image_question_for_testing() -> void:
+	load_questions_from_api(true, [], true)
+
+
+func _contains_question_with_media(question_list: Array) -> bool:
+	for question in question_list:
+		var media: Array = question.get("media", [])
+		if not media.is_empty():
+			return true
+	return false
+
+
 func clear_questions() -> void:
 	if request != null:
 		request.cancel_request()
@@ -195,6 +224,8 @@ func clear_questions() -> void:
 	last_rating_change = {}
 	pending_report_question_id = ""
 	pending_excluded_question_ids.clear()
+	pending_require_media = false
+	image_question_search_attempts = 0
 	questions_changed.emit()
 	ratings_changed.emit()
 

scripts/ui/question_player.gd

@@ -8,6 +8,9 @@ const TEXT_SCALE_MAX := 1.35
 const TEXT_SCALE_STEP := 0.1
 const REPORT_DETAILS_MIN := 10
 const REPORT_DETAILS_MAX := 2000
+const MEDIA_ZOOM_MIN := 0.25
+const MEDIA_ZOOM_MAX := 4.0
+const MEDIA_ZOOM_FACTOR := 1.25
 const REPORT_CATEGORIES := [
 	{"id": "clarity", "label": "Clarity"},
 	{"id": "medical_accuracy", "label": "Medical accuracy"},
@@ -84,6 +87,20 @@ var report_success_label: Label
 var report_is_submitting := false
 var report_question_id := ""
 var media_requests: Array[HTTPRequest] = []
+var question_media_items: Array = []
+var media_viewer_overlay: Control
+var media_viewer_background: ColorRect
+var media_viewer_scroll: ScrollContainer
+var media_viewer_center: CenterContainer
+var media_viewer_texture: TextureRect
+var media_viewer_position_label: Label
+var media_viewer_zoom_label: Label
+var media_viewer_previous_button: Button
+var media_viewer_next_button: Button
+var media_viewer_index := -1
+var media_viewer_zoom := 1.0
+var media_viewer_dragging := false
+var media_viewer_drag_position := Vector2.ZERO
 var red_fog_time := 0.0
 var green_fog_time := 0.0
 var correct_advance_delay := 0.0
@@ -331,7 +348,7 @@ func _ready() -> void:
 	explanation_label.bbcode_enabled = true
 	explanation_label.fit_content = true
 	explanation_label.scroll_active = false
-	explanation_label.custom_minimum_size = Vector2(0, 150)
+	explanation_label.custom_minimum_size = Vector2.ZERO
 	explanation_label.visible = false
 	_set_scaled_rich_text(explanation_label, 17)
 	question_content.add_child(explanation_label)
@@ -381,6 +398,7 @@ func _ready() -> void:
 
 	_build_labs_modal()
 	_build_report_modal()
+	_build_media_viewer()
 	resized.connect(_fit_modal_panels)
 	_fit_modal_panels()
 
@@ -403,6 +421,7 @@ func on_show(_payload: Variant = null) -> void:
 
 func on_hide() -> void:
 	awaiting_next_question = false
+	_hide_media_viewer()
 	_hide_report_modal(true)
 	_hide_labs_modal()
 
@@ -421,6 +440,21 @@ func _process(delta: float) -> void:
 
 
 func _input(event: InputEvent) -> void:
+	if media_viewer_overlay != null and media_viewer_overlay.visible:
+		if event.is_action_pressed("ui_cancel"):
+			_hide_media_viewer()
+		elif event.is_action_pressed("ui_left"):
+			_show_adjacent_media(-1)
+		elif event.is_action_pressed("ui_right"):
+			_show_adjacent_media(1)
+		elif event is InputEventKey and event.pressed and not event.echo and (event.keycode == KEY_PLUS or event.keycode == KEY_EQUAL):
+			_set_media_viewer_zoom(media_viewer_zoom * MEDIA_ZOOM_FACTOR)
+		elif event is InputEventKey and event.pressed and not event.echo and event.keycode == KEY_MINUS:
+			_set_media_viewer_zoom(media_viewer_zoom / MEDIA_ZOOM_FACTOR)
+		else:
+			return
+		get_viewport().set_input_as_handled()
+		return
 	if report_overlay != null and report_overlay.visible and event.is_action_pressed("ui_cancel"):
 		_hide_report_modal()
 		get_viewport().set_input_as_handled()
@@ -513,7 +547,7 @@ func _load_question() -> void:
 
 
 func _select_choice(index: int) -> void:
-	if pending_correct_advance or followup_required:
+	if pending_correct_advance or followup_required or _is_correct_answer_locked():
 		return
 	var choices := _get_presented_choices()
 	if index >= choices.size() or (BlockSessionService.mode == "Tutor" and not current_answer.is_empty()):
@@ -529,7 +563,7 @@ func _select_choice(index: int) -> void:
 
 
 func _clear_selected_choice() -> void:
-	if selected_choice == "":
+	if selected_choice == "" or _is_correct_answer_locked():
 		return
 	selected_choice = ""
 	if BlockSessionService.mode == "Timed":
@@ -596,7 +630,7 @@ func _skip_current_question() -> void:
 
 
 func _choice_gui_input(event: InputEvent, index: int) -> void:
-	if pending_correct_advance or followup_required:
+	if pending_correct_advance or followup_required or _is_correct_answer_locked():
 		return
 	var mouse_event := event as InputEventMouseButton
 	if mouse_event == null or mouse_event.button_index != MOUSE_BUTTON_RIGHT or not mouse_event.pressed:
@@ -622,7 +656,7 @@ func _choice_gui_input(event: InputEvent, index: int) -> void:
 
 
 func _toggle_eliminate_selected() -> void:
-	if pending_correct_advance or followup_required or selected_choice == "" or not current_answer.is_empty():
+	if pending_correct_advance or followup_required or selected_choice == "" or not current_answer.is_empty() or _is_correct_answer_locked():
 		return
 	var choices := _get_presented_choices()
 	for index in range(choices.size()):
@@ -726,10 +760,7 @@ func _show_answer_review() -> void:
 		skip_button.disabled = true
 		skip_button.visible = false
 	if question_scroll != null:
-		var review_target: Control = explanation_label
-		if references_container.visible:
-			review_target = references_container
-		question_scroll.call_deferred("ensure_control_visible", review_target)
+		question_scroll.call_deferred("ensure_control_visible", explanation_label)
 
 
 func _show_explanation() -> void:
@@ -990,6 +1021,8 @@ func _refresh_toolbar_state() -> void:
 
 func refresh_theme_controls() -> void:
 	_refresh_theme_button()
+	if media_viewer_background != null:
+		media_viewer_background.color = Style.BACKGROUND
 	if labs_button != null:
 		labs_button.icon = _make_labs_icon()
 	if flag_button != null:
@@ -1096,6 +1129,8 @@ func _load_question_media(question: Dictionary) -> void:
 		var media_url := _resolve_media_url(str(item))
 		if media_url == "":
 			continue
+		var media_index := question_media_items.size()
+		question_media_items.append({"texture": null, "loaded": false, "failed": false})
 		var frame := PanelContainer.new()
 		frame.size_flags_horizontal = Control.SIZE_EXPAND_FILL
 		frame.add_theme_stylebox_override("panel", Style.panel_box(Color("111a2a"), Color("344463")))
@@ -1111,18 +1146,27 @@ func _load_question_media(question: Dictionary) -> void:
 		_set_scaled_label(status, 15, Style.MUTED)
 		image_box.add_child(status)
 
+		var preview := Control.new()
+		preview.visible = false
+		preview.custom_minimum_size = Vector2(0, 260)
+		preview.size_flags_horizontal = Control.SIZE_EXPAND_FILL
+		preview.mouse_default_cursor_shape = Control.CURSOR_POINTING_HAND
+		preview.tooltip_text = "Open enlarged image"
+		preview.gui_input.connect(func(event: InputEvent): _media_preview_gui_input(event, media_index))
+		image_box.add_child(preview)
+
 		var texture_rect := TextureRect.new()
 		texture_rect.visible = false
-		texture_rect.expand_mode = TextureRect.EXPAND_FIT_WIDTH
+		texture_rect.mouse_filter = Control.MOUSE_FILTER_IGNORE
+		texture_rect.set_anchors_and_offsets_preset(Control.PRESET_FULL_RECT)
+		texture_rect.expand_mode = TextureRect.EXPAND_IGNORE_SIZE
 		texture_rect.stretch_mode = TextureRect.STRETCH_KEEP_ASPECT_CENTERED
-		texture_rect.custom_minimum_size = Vector2(0, 260)
-		texture_rect.size_flags_horizontal = Control.SIZE_EXPAND_FILL
-		image_box.add_child(texture_rect)
+		preview.add_child(texture_rect)
 
 		var request := HTTPRequest.new()
 		request.request_completed.connect(
 			func(result: int, response_code: int, _headers: PackedStringArray, body: PackedByteArray):
-				_on_media_loaded(result, response_code, body, question_id, texture_rect, status)
+				_on_media_loaded(result, response_code, body, question_id, media_index, preview, texture_rect, status)
 		)
 		media_requests.append(request)
 		add_child(request)
@@ -1132,10 +1176,12 @@ func _load_question_media(question: Dictionary) -> void:
 
 
 func _clear_question_media() -> void:
+	_hide_media_viewer()
 	for request in media_requests:
 		if is_instance_valid(request):
 			request.queue_free()
 	media_requests.clear()
+	question_media_items.clear()
 	if media_container == null:
 		return
 	for child in media_container.get_children():
@@ -1167,12 +1213,16 @@ func _on_media_loaded(
 	response_code: int,
 	body: PackedByteArray,
 	question_id: String,
+	media_index: int,
+	preview: Control,
 	texture_rect: TextureRect,
 	status: Label) -> void:
 	if str(BlockSessionService.get_current_question().get("id", "")) != question_id:
 		return
 	if result != HTTPRequest.RESULT_SUCCESS or response_code < 200 or response_code >= 300:
 		status.text = "Image unavailable."
+		if media_index < question_media_items.size():
+			question_media_items[media_index]["failed"] = true
 		return
 
 	var image := Image.new()
@@ -1183,13 +1233,207 @@ func _on_media_loaded(
 		err = image.load_webp_from_buffer(body)
 	if err != OK:
 		status.text = "Image unavailable."
+		if media_index < question_media_items.size():
+			question_media_items[media_index]["failed"] = true
 		return
 
-	texture_rect.texture = ImageTexture.create_from_image(image)
+	var texture := ImageTexture.create_from_image(image)
+	question_media_items[media_index]["texture"] = texture
+	question_media_items[media_index]["loaded"] = true
+	texture_rect.texture = texture
 	texture_rect.visible = true
+	preview.visible = true
 	status.visible = false
 
 
+func _build_media_viewer() -> void:
+	media_viewer_overlay = Control.new()
+	media_viewer_overlay.visible = false
+	media_viewer_overlay.top_level = true
+	media_viewer_overlay.mouse_filter = Control.MOUSE_FILTER_STOP
+	media_viewer_overlay.set_anchors_and_offsets_preset(Control.PRESET_FULL_RECT)
+	add_child(media_viewer_overlay)
+
+	media_viewer_background = ColorRect.new()
+	media_viewer_background.color = Style.BACKGROUND
+	media_viewer_background.mouse_filter = Control.MOUSE_FILTER_STOP
+	media_viewer_background.set_anchors_and_offsets_preset(Control.PRESET_FULL_RECT)
+	media_viewer_overlay.add_child(media_viewer_background)
+
+	var layout := VBoxContainer.new()
+	layout.set_anchors_and_offsets_preset(Control.PRESET_FULL_RECT)
+	layout.offset_left = 16
+	layout.offset_top = 12
+	layout.offset_right = -16
+	layout.offset_bottom = -16
+	layout.add_theme_constant_override("separation", 10)
+	media_viewer_overlay.add_child(layout)
+
+	var toolbar := HBoxContainer.new()
+	toolbar.add_theme_constant_override("separation", 8)
+	layout.add_child(toolbar)
+
+	media_viewer_position_label = Label.new()
+	media_viewer_position_label.size_flags_horizontal = Control.SIZE_EXPAND_FILL
+	_set_scaled_label(media_viewer_position_label, 17, Style.TEXT)
+	toolbar.add_child(media_viewer_position_label)
+
+	media_viewer_previous_button = _make_media_viewer_button("<", "Previous image")
+	media_viewer_previous_button.pressed.connect(func(): _show_adjacent_media(-1))
+	toolbar.add_child(media_viewer_previous_button)
+	media_viewer_next_button = _make_media_viewer_button(">", "Next image")
+	media_viewer_next_button.pressed.connect(func(): _show_adjacent_media(1))
+	toolbar.add_child(media_viewer_next_button)
+
+	var zoom_out := _make_media_viewer_button("-", "Zoom out")
+	zoom_out.pressed.connect(func(): _set_media_viewer_zoom(media_viewer_zoom / MEDIA_ZOOM_FACTOR))
+	toolbar.add_child(zoom_out)
+	media_viewer_zoom_label = Label.new()
+	media_viewer_zoom_label.custom_minimum_size = Vector2(64, 44)
+	media_viewer_zoom_label.horizontal_alignment = HORIZONTAL_ALIGNMENT_CENTER
+	media_viewer_zoom_label.vertical_alignment = VERTICAL_ALIGNMENT_CENTER
+	_set_scaled_label(media_viewer_zoom_label, 15, Style.TEXT)
+	toolbar.add_child(media_viewer_zoom_label)
+	var zoom_in := _make_media_viewer_button("+", "Zoom in")
+	zoom_in.pressed.connect(func(): _set_media_viewer_zoom(media_viewer_zoom * MEDIA_ZOOM_FACTOR))
+	toolbar.add_child(zoom_in)
+	var fit_button := _make_media_viewer_button("Fit", "Fit image to window", Vector2(60, 44))
+	fit_button.pressed.connect(_fit_media_viewer_image)
+	toolbar.add_child(fit_button)
+	var close_button := _make_media_viewer_button("X", "Close image viewer")
+	close_button.pressed.connect(_hide_media_viewer)
+	toolbar.add_child(close_button)
+
+	media_viewer_scroll = ScrollContainer.new()
+	media_viewer_scroll.size_flags_vertical = Control.SIZE_EXPAND_FILL
+	media_viewer_scroll.size_flags_horizontal = Control.SIZE_EXPAND_FILL
+	media_viewer_scroll.gui_input.connect(_media_viewer_gui_input)
+	layout.add_child(media_viewer_scroll)
+
+	media_viewer_center = CenterContainer.new()
+	media_viewer_center.size_flags_horizontal = Control.SIZE_EXPAND_FILL
+	media_viewer_center.size_flags_vertical = Control.SIZE_EXPAND_FILL
+	media_viewer_scroll.add_child(media_viewer_center)
+
+	media_viewer_texture = TextureRect.new()
+	media_viewer_texture.expand_mode = TextureRect.EXPAND_IGNORE_SIZE
+	media_viewer_texture.stretch_mode = TextureRect.STRETCH_KEEP_ASPECT_CENTERED
+	media_viewer_texture.mouse_filter = Control.MOUSE_FILTER_IGNORE
+	media_viewer_center.add_child(media_viewer_texture)
+
+
+func _make_media_viewer_button(text_value: String, tooltip: String, minimum := Vector2(44, 44)) -> Button:
+	var button := Button.new()
+	button.text = text_value
+	button.tooltip_text = tooltip
+	button.custom_minimum_size = minimum
+	Style.style_chip(button, Style.CYAN)
+	UISoundService.set_button_sound(button, "toggle")
+	return button
+
+
+func _media_preview_gui_input(event: InputEvent, media_index: int) -> void:
+	if event is InputEventMouseButton and event.button_index == MOUSE_BUTTON_LEFT and event.pressed:
+		_show_media_viewer(media_index)
+		accept_event()
+	elif event is InputEventScreenTouch and event.pressed:
+		_show_media_viewer(media_index)
+		accept_event()
+
+
+func _show_media_viewer(index: int) -> void:
+	if index < 0 or index >= question_media_items.size():
+		return
+	if not bool(question_media_items[index].get("loaded", false)):
+		return
+	var texture := question_media_items[index].get("texture") as Texture2D
+	if texture == null:
+		return
+	media_viewer_index = index
+	media_viewer_texture.texture = texture
+	media_viewer_overlay.visible = true
+	media_viewer_overlay.move_to_front()
+	_update_media_viewer_navigation()
+	call_deferred("_fit_media_viewer_image")
+
+
+func _hide_media_viewer() -> void:
+	media_viewer_dragging = false
+	media_viewer_index = -1
+	if media_viewer_overlay != null:
+		media_viewer_overlay.visible = false
+
+
+func _show_adjacent_media(direction: int) -> void:
+	var next_index := _find_loaded_media_index(media_viewer_index, direction)
+	if next_index >= 0:
+		_show_media_viewer(next_index)
+
+
+func _find_loaded_media_index(from_index: int, direction: int) -> int:
+	var index := from_index + direction
+	while index >= 0 and index < question_media_items.size():
+		if bool(question_media_items[index].get("loaded", false)):
+			return index
+		index += direction
+	return -1
+
+
+func _update_media_viewer_navigation() -> void:
+	media_viewer_position_label.text = "Image %d of %d" % [media_viewer_index + 1, question_media_items.size()]
+	media_viewer_previous_button.disabled = _find_loaded_media_index(media_viewer_index, -1) < 0
+	media_viewer_next_button.disabled = _find_loaded_media_index(media_viewer_index, 1) < 0
+
+
+func _fit_media_viewer_image() -> void:
+	if media_viewer_texture == null or media_viewer_texture.texture == null:
+		return
+	var image_size := media_viewer_texture.texture.get_size()
+	var available := media_viewer_scroll.size - Vector2(24, 24)
+	if image_size.x <= 0.0 or image_size.y <= 0.0 or available.x <= 0.0 or available.y <= 0.0:
+		return
+	_set_media_viewer_zoom(minf(available.x / image_size.x, available.y / image_size.y))
+
+
+func _set_media_viewer_zoom(value: float) -> void:
+	if media_viewer_texture == null or media_viewer_texture.texture == null:
+		return
+	media_viewer_zoom = clampf(value, MEDIA_ZOOM_MIN, MEDIA_ZOOM_MAX)
+	var scaled_size := media_viewer_texture.texture.get_size() * media_viewer_zoom
+	media_viewer_texture.custom_minimum_size = scaled_size
+	media_viewer_center.custom_minimum_size = Vector2(
+		maxf(media_viewer_scroll.size.x, scaled_size.x),
+		maxf(media_viewer_scroll.size.y, scaled_size.y))
+	media_viewer_zoom_label.text = "%d%%" % int(round(media_viewer_zoom * 100.0))
+
+
+func _media_viewer_gui_input(event: InputEvent) -> void:
+	if event is InputEventMouseButton:
+		if event.button_index == MOUSE_BUTTON_WHEEL_UP and event.pressed:
+			_set_media_viewer_zoom(media_viewer_zoom * MEDIA_ZOOM_FACTOR)
+			accept_event()
+		elif event.button_index == MOUSE_BUTTON_WHEEL_DOWN and event.pressed:
+			_set_media_viewer_zoom(media_viewer_zoom / MEDIA_ZOOM_FACTOR)
+			accept_event()
+		elif event.button_index == MOUSE_BUTTON_LEFT:
+			media_viewer_dragging = event.pressed
+			media_viewer_drag_position = event.position
+			accept_event()
+	elif event is InputEventMouseMotion and media_viewer_dragging:
+		var drag_delta: Vector2 = event.position - media_viewer_drag_position
+		media_viewer_drag_position = event.position
+		media_viewer_scroll.scroll_horizontal -= int(drag_delta.x)
+		media_viewer_scroll.scroll_vertical -= int(drag_delta.y)
+		accept_event()
+	elif event is InputEventMagnifyGesture:
+		_set_media_viewer_zoom(media_viewer_zoom * event.factor)
+		accept_event()
+	elif event is InputEventScreenDrag:
+		media_viewer_scroll.scroll_horizontal -= int(event.relative.x)
+		media_viewer_scroll.scroll_vertical -= int(event.relative.y)
+		accept_event()
+
+
 func _build_report_modal() -> void:
 	report_overlay = Control.new()
 	report_overlay.visible = false
@@ -1639,11 +1883,12 @@ func _subtract_highlight_range(highlights: Array, start: int, end: int) -> bool:
 
 func _apply_saved_choice_state() -> void:
 	var choices := _get_presented_choices()
+	var answer_is_locked := _is_correct_answer_locked()
 	for index in range(choices.size()):
 		var id := str(choices[index].get("id", ""))
 		var has_followup_panel := index < choice_followup_panels.size() and choice_followup_panels[index].visible
 		_set_choice_button_text(index, choices[index])
-		choice_buttons[index].disabled = locked_wrong_choice_ids.has(id) and not has_followup_panel
+		choice_buttons[index].disabled = answer_is_locked or (locked_wrong_choice_ids.has(id) and not has_followup_panel)
 		_style_choice_button_for_state(index, id)
 		if locked_wrong_choice_ids.has(id):
 			choice_buttons[index].modulate = Color(1.0, 0.25, 0.25) if Style.is_dark else Color.WHITE
@@ -1665,6 +1910,10 @@ func _apply_saved_choice_state() -> void:
 	_refresh_submit_state()
 
 
+func _is_correct_answer_locked() -> bool:
+	return bool(current_answer.get("is_correct", false))
+
+
 func _refresh_submit_state() -> void:
 	if next_button == null:
 		return

scripts/ui/study_selector.gd

@@ -11,6 +11,7 @@ var question_bank_button: Button
 var bank_status_label: Label
 var bank_error_label: Label
 var retry_button: Button
+var image_question_test_link: LinkButton
 var current_stage := "exam"
 var pending_question_bank_launch := false
 
@@ -152,6 +153,15 @@ func _build_mode_view() -> void:
 	retry_button.pressed.connect(_retry_question_bank)
 	mode_view.add_child(retry_button)
 
+	image_question_test_link = LinkButton.new()
+	image_question_test_link.text = "Temporary: test a question with an image"
+	image_question_test_link.tooltip_text = "Load a random published question that includes media"
+	image_question_test_link.size_flags_horizontal = Control.SIZE_SHRINK_BEGIN
+	image_question_test_link.add_theme_color_override("font_color", Style.CYAN)
+	image_question_test_link.add_theme_color_override("font_hover_color", Style.MAGENTA)
+	image_question_test_link.pressed.connect(_select_image_question_for_testing)
+	mode_view.add_child(image_question_test_link)
+
 	var spacer := Control.new()
 	spacer.size_flags_vertical = Control.SIZE_EXPAND_FILL
 	mode_view.add_child(spacer)
@@ -196,6 +206,12 @@ func _retry_question_bank() -> void:
 	_refresh_bank_state()
 
 
+func _select_image_question_for_testing() -> void:
+	pending_question_bank_launch = true
+	QuestionBankService.load_image_question_for_testing()
+	_refresh_bank_state()
+
+
 func _on_questions_changed() -> void:
 	_refresh_bank_state()
 	if pending_question_bank_launch and visible and current_stage == "step3" and QuestionBankService.load_state == "ready":
@@ -213,6 +229,7 @@ func _refresh_bank_state() -> void:
 		return
 	var state := QuestionBankService.load_state
 	question_bank_button.disabled = pending_question_bank_launch
+	image_question_test_link.disabled = pending_question_bank_launch
 	retry_button.visible = state == "failed" or state == "retrying"
 	retry_button.disabled = state == "retrying"
 	bank_error_label.text = QuestionBankService.last_error if state == "failed" or state == "retrying" else ""

tests/media_viewer_test.gd

@@ -0,0 +1,57 @@
+extends SceneTree
+
+var failures := 0
+
+
+func _initialize() -> void:
+	_test_loaded_media_navigation()
+	_test_zoom_limits()
+	_test_image_question_detection()
+	quit(1 if failures > 0 else 0)
+
+
+func _test_loaded_media_navigation() -> void:
+	var player = load("res://scripts/ui/question_player.gd").new()
+	player.question_media_items = [
+		{"loaded": true},
+		{"loaded": false},
+		{"loaded": true}
+	]
+	_assert(player._find_loaded_media_index(0, 1) == 2, "navigation should skip images that have not loaded")
+	_assert(player._find_loaded_media_index(2, -1) == 0, "back navigation should preserve source order")
+	_assert(player._find_loaded_media_index(2, 1) == -1, "navigation should stop at the final image")
+	player.free()
+
+
+func _test_zoom_limits() -> void:
+	var player = load("res://scripts/ui/question_player.gd").new()
+	player.media_viewer_scroll = ScrollContainer.new()
+	player.media_viewer_scroll.size = Vector2(800, 600)
+	player.media_viewer_center = CenterContainer.new()
+	player.media_viewer_texture = TextureRect.new()
+	player.media_viewer_zoom_label = Label.new()
+	var image := Image.create(100, 50, false, Image.FORMAT_RGBA8)
+	player.media_viewer_texture.texture = ImageTexture.create_from_image(image)
+	player._set_media_viewer_zoom(20.0)
+	_assert(is_equal_approx(player.media_viewer_zoom, 4.0), "zoom should be capped at 400 percent")
+	player._set_media_viewer_zoom(0.01)
+	_assert(is_equal_approx(player.media_viewer_zoom, 0.25), "zoom should be capped at 25 percent")
+	player.media_viewer_scroll.free()
+	player.media_viewer_center.free()
+	player.media_viewer_texture.free()
+	player.media_viewer_zoom_label.free()
+	player.free()
+
+
+func _test_image_question_detection() -> void:
+	var service = load("res://scripts/autoload/question_bank_service.gd").new()
+	_assert(not service._contains_question_with_media([{"id": "plain", "media": []}]), "plain questions should not satisfy an image-only request")
+	_assert(service._contains_question_with_media([{"id": "image", "media": ["/media/example"]}]), "questions with media should satisfy an image-only request")
+	service.free()
+
+
+func _assert(condition: bool, message: String) -> void:
+	if condition:
+		return
+	failures += 1
+	push_error(message)

tests/media_viewer_test.gd.uid

@@ -0,0 +1 @@
+uid://b34pl1b02ehr6

tests/post_answer_review_test.gd

@@ -7,6 +7,7 @@ func _initialize() -> void:
 	_test_reference_normalization()
 	_test_reference_url_filter()
 	_test_correct_feedback_does_not_auto_advance()
+	_test_correct_review_locks_answer_interactions()
 	quit(1 if failures > 0 else 0)
 
 
@@ -58,6 +59,21 @@ func _test_correct_feedback_does_not_auto_advance() -> void:
 	player.free()
 
 
+func _test_correct_review_locks_answer_interactions() -> void:
+	var player = load("res://scripts/ui/question_player.gd").new()
+	player.current_answer = {"is_correct": true}
+	player.selected_choice = "A"
+	player.presented_choices = [{"id": "A", "text": "First"}, {"id": "B", "text": "Second"}]
+	player._select_choice(1)
+	_assert(player.selected_choice == "A", "correct review should reject answer selection changes")
+	var right_click := InputEventMouseButton.new()
+	right_click.button_index = MOUSE_BUTTON_RIGHT
+	right_click.pressed = true
+	player._choice_gui_input(right_click, 1)
+	_assert(player.eliminated.is_empty(), "correct review should reject answer strike-through changes")
+	player.free()
+
+
 func _assert(condition: bool, message: String) -> void:
 	if condition:
 		return