TITANIC: Implement PET Text scrolling

4 files changed, 96 insertions, 10 deletions

diff --git a/engines/titanic/pet_control/pet_conversations.cpp b/engines/titanic/pet_control/pet_conversations.cpp
index 3afd5ee380..d2c891efb8 100644
--- a/engines/titanic/pet_control/pet_conversations.cpp
+++ b/engines/titanic/pet_control/pet_conversations.cpp
@@ -21,6 +21,7 @@
  */
 
 #include "titanic/pet_control/pet_conversations.h"
+#include "titanic/pet_control/pet_control.h"
 
 namespace Titanic {
 
@@ -44,6 +45,14 @@ bool CPetConversations::isValid(CPetControl *petControl) {
 	return setupControl(petControl);
 }
 
+bool CPetConversations::MouseButtonDownMsg(CMouseButtonDownMsg *msg) {
+	return
+		_scrollUp.MouseButtonDownMsg(msg->_mousePos) ||
+		_scrollDown.MouseButtonDownMsg(msg->_mousePos) ||
+		_val7.MouseButtonDownMsg(msg->_mousePos) ||
+		_val8.MouseButtonDownMsg(msg->_mousePos);
+}
+
 bool CPetConversations::setupControl(CPetControl *petControl) {
 	if (petControl) {
 		_petControl = petControl;
@@ -60,10 +69,10 @@ bool CPetConversations::setupControl(CPetControl *petControl) {
 		_gfxList[2].translate(20, 434);
 
 		const Rect rect2(0, 0, 11, 24);
-		_val1.setBounds(rect2);
-		_val1.translate(87, 374);
-		_val2.setBounds(rect2);
-		_val2.translate(87, 421);
+		_scrollUp.setBounds(rect2);
+		_scrollUp.translate(87, 374);
+		_scrollDown.setBounds(rect2);
+		_scrollDown.translate(87, 421);
 
 		const Rect rect3(0, 0, 39, 39);
 		_val7.setBounds(rect3);
@@ -86,4 +95,16 @@ bool CPetConversations::setupControl(CPetControl *petControl) {
 	return true;
 }
 
+void CPetConversations::scrollDown() {
+	_log.scrollDown(CScreenManager::_screenManagerPtr);
+	if (_petControl)
+		_petControl->makeDirty();
+}
+
+void CPetConversations::scrollUp() {
+	_log.scrollUp(CScreenManager::_screenManagerPtr);
+	if (_petControl)
+		_petControl->makeDirty();
+}
+
 } // End of namespace Titanic
diff --git a/engines/titanic/pet_control/pet_conversations.h b/engines/titanic/pet_control/pet_conversations.h
index 89dbc5eb96..8a3ca886a5 100644
--- a/engines/titanic/pet_control/pet_conversations.h
+++ b/engines/titanic/pet_control/pet_conversations.h
@@ -31,8 +31,8 @@ namespace Titanic {
 
 class CPetConversations : public CPetSection {
 private:
-	CPetGfxElement _val1;
-	CPetGfxElement _val2;
+	CPetGfxElement _scrollUp;
+	CPetGfxElement _scrollDown;
 	CPetGfxElement _val3;
 	CPetGfxElement _gfxList[3];
 	CPetGfxElement _val4;
@@ -55,6 +55,16 @@ private:
 	 * Sets up the control
 	 */
 	bool setupControl(CPetControl *petControl);
+
+	/**
+	 * Scroll down the conversation log
+	 */
+	void scrollDown();
+
+	/**
+	 * Scroll up the conversation log
+	 */
+	void scrollUp();
 public:
 	CPetConversations();
 
@@ -72,6 +82,12 @@ public:
 	 * Returns true if the object is in a valid state
 	 */
 	virtual bool isValid(CPetControl *petControl);
+
+	/**
+	 * Following are handlers for the various messages that the PET can
+	 * pass onto the currently active section/area
+	 */
+	virtual bool MouseButtonDownMsg(CMouseButtonDownMsg *msg);
 };
 
 } // End of namespace Titanic
diff --git a/engines/titanic/pet_control/pet_text.cpp b/engines/titanic/pet_control/pet_text.cpp
index 3a10ab4c87..9a895de36b 100644
--- a/engines/titanic/pet_control/pet_text.cpp
+++ b/engines/titanic/pet_control/pet_text.cpp
@@ -30,7 +30,7 @@ CPetText::CPetText(uint count) :
 		_backR(0xff), _backG(0xff), _backB(0xff), 
 		_textR(0), _textG(0), _textB(200),
 		_fontNumber2(0), _field64(0), _field68(0), _field6C(0),
-		_hasBorder(true), _field74(0), _textCursor(nullptr), _field7C(0) {
+		_hasBorder(true), _scrollTop(0), _textCursor(nullptr), _field7C(0) {
 	setupArrays(count);
 }
 
@@ -97,7 +97,7 @@ void CPetText::load(SimpleFile *file, int param) {
 		_textG = file->readNumber();
 		_textB = file->readNumber();
 		_hasBorder = file->readNumber() != 0;
-		_field74 = file->readNumber();
+		_scrollTop = file->readNumber();
 
 		warning("TODO: CPetText::load %d,%d", var1, var2);
 		assert(_array.size() >= count);
@@ -140,7 +140,7 @@ void CPetText::draw(CScreenManager *screenManager) {
 	tempRect.grow(-2);
 	screenManager->setFontNumber(_fontNumber2);
 
-	screenManager->writeString(SURFACE_BACKBUFFER, tempRect, _field74, _lines, _textCursor);
+	screenManager->writeString(SURFACE_BACKBUFFER, tempRect, _scrollTop, _lines, _textCursor);
 
 	screenManager->setFontNumber(_fontNumber1);
 }
@@ -250,4 +250,33 @@ void CPetText::setNPC(int val1, int npcId) {
 	_field68 = npcId;
 }
 
+void CPetText::scrollUp(CScreenManager *screenManager) {
+	int oldFontNumber = screenManager->setFontNumber(_fontNumber2);
+	_scrollTop -= screenManager->getFontHeight();
+	constrainScrollUp(screenManager);
+	screenManager->setFontNumber(oldFontNumber);
+}
+
+void CPetText::scrollDown(CScreenManager *screenManager) {
+	int oldFontNumber = screenManager->setFontNumber(_fontNumber2);
+	_scrollTop += screenManager->getFontHeight();
+	constrainScrollDown(screenManager);
+	screenManager->setFontNumber(oldFontNumber);
+}
+
+void CPetText::constrainScrollUp(CScreenManager *screenManager) {
+	if (_scrollTop < 0)
+		_scrollTop = 0;
+}
+
+void CPetText::constrainScrollDown(CScreenManager *screenManager) {
+	// Figure out the maximum scroll amount allowed
+	int maxScroll = _bounds.height() - getTextHeight(screenManager) - 4;
+	if (maxScroll < 0)
+		maxScroll = 0;
+
+	if (_scrollTop > maxScroll)
+		_scrollTop = maxScroll;
+}
+
 } // End of namespace Titanic
diff --git a/engines/titanic/pet_control/pet_text.h b/engines/titanic/pet_control/pet_text.h
index 6ce1903166..36d098f141 100644
--- a/engines/titanic/pet_control/pet_text.h
+++ b/engines/titanic/pet_control/pet_text.h
@@ -57,7 +57,7 @@ private:
 	int _field68;
 	int _field6C;
 	bool _hasBorder;
-	int _field74;
+	int _scrollTop;
 	CTextCursor *_textCursor;
 	int _field7C;
 private:
@@ -81,6 +81,16 @@ private:
 	 * Get the required height to draw the text
 	 */
 	int getTextHeight(CScreenManager *screenManager);
+
+	/**
+	 * Ensures the Y scrolling for the text is in the valid range
+	 */
+	void constrainScrollUp(CScreenManager *screenManager);
+
+	/**
+	 * Ensures the Y scrolling for the text is in the valid range
+	 */
+	void constrainScrollDown(CScreenManager *screenManager);
 public:
 	CPetText(uint count = 10);
 
@@ -157,6 +167,16 @@ public:
 	 * Get the font
 	 */
 	int getFontNumber() const { return _fontNumber1; }
+
+	/**
+	 * Scroll the text up
+	 */
+	void scrollUp(CScreenManager *screenManager);
+
+	/**
+	 * Scroll the text down
+	 */
+	void scrollDown(CScreenManager *screenManager);
 };
 
 } // End of namespace Titanic