Game chat box

Introduction

This snippet implements a chat box that can display text in 3 font sizes as well as limiting the number of entries (history) to a certain number. Please discuss this article within the GameChatBox thread.

.layout Special Features

The layout definition is deceptively simple. It defines a FrameWindow containing two widgets; a Listbox in the upper region for chat history and an Editbox at the lower region for text input.

What is not apparent is how the bottom portion of the Listbox and the entire Editbox are defined; they specify a proportion of 100% of their parent but with a negative offset. Essentially the bottom of the Listbox extends to the bottom of the FrameWindow (the parent) and is then moved "up" to make room for the Editbox. And the Editbox follows the same pattern. This allows the Editbox to retain its height as the parent FrameWindow is resized.

Creating the necessary .font files

A .font file is a simple text file that defines a font within Cegui. They are located within the datafiles\fonts directory.

This snippet uses the Commonwealth font in sizes 10, 36, and 72. To create the missing font definitions for sizes 36 and 72 simply make two copies of the existing "Commonwealth-10.font" file. The first copy is to be named "Commonwealth-36.font" and the second copy "Commonwealth-72.font". Edit the "Commonwealth-36.font" file and replace the value "10" by the value "36". Similarly edit the "Commonwealth-72.font" file and replace the value "10" by the value "72".

Another approach is to dynamically create fonts. For more details consult DynamicFont

Files

ChatBox_demo.h

<cpp/>

1. ifndef _ChatBox_h_
2. define _ChatBox_h_

1. include "CEGuiSample.h"
2. include "CEGUI.h"
3. include "CEGUIXMLAttributes.h"

class DemoSample : public CEGuiSample { public:

   bool initialiseSample()

{ using namespace CEGUI; try { // Retrieve the window manager WindowManager& winMgr = WindowManager::getSingleton();

// Load the TaharezLook scheme and set up the default mouse cursor and font SchemeManager::getSingleton().loadScheme("TaharezLook.scheme"); System::getSingleton().setDefaultMouseCursor("TaharezLook", "MouseArrow"); if(!FontManager::getSingleton().isFontPresent("Commonwealth-10")) FontManager::getSingleton().createFont("Commonwealth-10.font");

// Set the GUI Sheet Window* sheet = winMgr.createWindow("DefaultWindow", "root_wnd"); System::getSingleton().setGUISheet(sheet);

// Load a layout Window* guiLayout = winMgr.loadWindowLayout("ChatBox.layout"); sheet->addChildWindow(guiLayout);

// Obtain the handles of some widgets Window* historySize = winMgr.getWindow("/ChatBox/History"); Window* fontName = winMgr.getWindow("/ChatBox/FontName"); Spinner* fontSize = static_cast<Spinner*>(winMgr.getWindow("/ChatBox/FontSize")); Window* chatText = winMgr.getWindow("/ChatBox/Text");

// Disable widgets until a valid font is registered fontName->setEnabled(false); fontSize->setEnabled(false); chatText->setEnabled(false);

// Retrieve the design-specified values mHistorySize = static_cast<size_t>(PropertyHelper::stringToUint(historySize->getText())); mDefaultFontSize = fontSize->getText(); mChatFontName = fontName->getText(); setHistorySize(mHistorySize); fontName->setText("");

// Configure the history size // Pressing <ENTER> changes the maximal number of entries within the history Listbox historySize->subscribeEvent(Editbox::EventTextAccepted, Event::Subscriber(&DemoSample::Event_HistorySizeChange, this));

// Configure the text Editbox // Pressing <ENTER> puts the text into the history Listbox chatText->subscribeEvent(Editbox::EventTextAccepted, Event::Subscriber(&DemoSample::Event_ChatTextAdded, this));

// Configure the font name Combobox // Selecting a name changes the font used in the history Listbox and the text Editbox fontName->subscribeEvent(Combobox::EventTextChanged, Event::Subscriber(&DemoSample::Event_FontChange, this));

// Configure the font size Spinner // Selecting a size changes the font size used in the history Listbox and the text Editbox fontSize->subscribeEvent(Spinner::EventValueChanged, Event::Subscriber(&DemoSample::Event_FontChange, this)); fontSize->setTextInputMode(Spinner::Integer); fontSize->setMinimumValue(4.0f); fontSize->setMaximumValue(72.0f); fontSize->setStepSize(1.0f); fontSize->setCurrentValue(PropertyHelper::stringToFloat(mDefaultFontSize));

// Initialize the list of fonts // The first registered font becomes the active font registerFont("Commonwealth", "Commonv2c.ttf"); registerFont("DejaVuSans", "DejaVuSans.ttf"); registerFont("Iconified", "Iconiv2.ttf"); registerFont("MissingFile", "MissingFile.ttf"); // What happens if a font is missing? registerFont("Pixmap Font", "FairChar-30.font"); // And what about a non-Freetype font? } catch(Exception &e) { #if defined( __WIN32__ ) || defined( _WIN32 ) MessageBox(NULL, e.getMessage().c_str(), "Error initializing the demo", MB_OK | MB_ICONERROR | MB_TASKMODAL); #else std::cerr << "Error initializing the demo:" << e.getMessage().c_str() << "\n"; #endif }

return true; }

void cleanupSample(void) { }

bool Event_HistorySizeChange(const CEGUI::EventArgs& args) { using namespace CEGUI;

WindowManager& winMgr = WindowManager::getSingleton(); CEGUI::Window* historySize = winMgr.getWindow("/ChatBox/History"); int size = PropertyHelper::stringToInt( historySize->getText() ); setHistorySize(size); return true; }

bool Event_ChatTextAdded(const CEGUI::EventArgs& args) { using namespace CEGUI;

WindowManager& winMgr = WindowManager::getSingleton(); Editbox* chatText = static_cast<Editbox*> (winMgr.getWindow("/ChatBox/Text")); addChatText(chatText->getText());

// Clear the text in the Editbox chatText->setText(""); return true; }

bool Event_FontChange(const CEGUI::EventArgs& args) { using namespace CEGUI; WindowManager& winMgr = WindowManager::getSingleton(); Window* fontName = winMgr.getWindow("/ChatBox/FontName"); String name = fontName->getText();

Spinner* fontSize = static_cast<Spinner*>(winMgr.getWindow("/ChatBox/FontSize")); String size = PropertyHelper::floatToString(fontSize->getCurrentValue());

Window* chatText = winMgr.getWindow("/ChatBox/Text"); chatText->setText(name + " - " + size);

changeFont(name, size); return true; }

void setHistorySize(const size_t& pSize) { using namespace CEGUI;

if(pSize > 0) { // A better validation would be to enforce a minimal and a maximal size mHistorySize = pSize;

WindowManager& winMgr = WindowManager::getSingleton(); Listbox* chatHistory = static_cast<Listbox*> (winMgr.getWindow("/ChatBox/List")); ListboxItem* chatItem; while(chatHistory->getItemCount() > mHistorySize) { // There are too many items within the history Listbox, purging them one at a time chatItem = chatHistory->getListboxItemFromIndex(0); chatHistory->removeItem(chatItem); } } }

void addChatText(const CEGUI::String& pText) { using namespace CEGUI;

WindowManager& winMgr = WindowManager::getSingleton(); Listbox* chatHistory = static_cast<Listbox*> (winMgr.getWindow("/ChatBox/List"));

// If there's text then add it if(pText.size()) { // Add the Editbox text to the history Listbox ListboxTextItem* chatItem; if(chatHistory->getItemCount() == mHistorySize) { /* We have reached the capacity of the Listbox so re-use the first Listbox item. This code is a little crafty. By default the ListboxTextItem is created with the auto-delete flag set to true, which results in its automatic deletion when removed from the Listbox. So we change that flag to false, extract the item from the Listbox, change its text, put the auto-delete flag back to true, and finally put the item back into the Listbox. */ chatItem = static_cast<ListboxTextItem*>(chatHistory->getListboxItemFromIndex(0)); chatItem->setAutoDeleted(false); chatHistory->removeItem(chatItem); chatItem->setAutoDeleted(true); chatItem->setText(pText); } else { // Create a new listbox item chatItem = new ListboxTextItem(pText); } chatHistory->addItem(chatItem); chatHistory->ensureItemIsVisible(chatHistory->getItemCount()); } }

void registerFont(const CEGUI::String& pLogicalName, const CEGUI::String& pFileName) { using namespace CEGUI;

// Ensure that font names are registered only once if(mFontList.find(pLogicalName) == mFontList.end()) { // Test the font so that only valid fonts are available String testFont = mChatFontName; if(mFontList.size() != 0) { // If the list is empty then attempt to create the font using the "real" font name // Otherwise use a "test" font name so as not to corrupt the "real" one testFont += "__test_font__"; } Font* font = makeFont(testFont, pFileName, mDefaultFontSize); if(mFontList.size() != 0 && FontManager::getSingleton().isFontPresent(testFont)) { // Since this was only a test font we destroy it FontManager::getSingleton().destroyFont(testFont); } if(!font) { // This font is invalid if(FontManager::getSingleton().isFontPresent(testFont)) return; else return; }

WindowManager& winMgr = WindowManager::getSingleton(); Combobox* fontName = static_cast<Combobox*>(winMgr.getWindow("/ChatBox/FontName")); mFontList[pLogicalName] = pFileName; ListboxTextItem* fontNameItem = new ListboxTextItem(pLogicalName); fontNameItem->setSelectionBrushImage("TaharezLook", "MultiListSelectionBrush"); fontName->addItem(fontNameItem); if(fontName->getItemCount() == 1) { // Enable widgets now that at least one valid font has been found Spinner* fontSize = static_cast<Spinner*>(winMgr.getWindow("/ChatBox/FontSize")); Window* chatText = winMgr.getWindow("/ChatBox/Text"); fontName->setEnabled(true); fontSize->setEnabled(true); chatText->setEnabled(true);

// The first registered font becomes the active font fontName->setText(pLogicalName); // This triggers a call to changeFont fontName->setItemSelectState(fontNameItem, true); } } }

protected: CEGUI::Font* makeFont(const CEGUI::String& pFontName, const CEGUI::String& pFileName, const CEGUI::String& pSize) { using namespace CEGUI;

Font* font; try { if(FontManager::getSingleton().isFontPresent(pFontName)) { // The chat font is reused rather than deleted and recreated // every time an attribute changes. For this reason it is // important to use a unique logical name for the font. font = FontManager::getSingleton().getFont(pFontName); font->setProperty("FileName", pFileName); font->setProperty("PointSize", pSize); } else { // This is the first time we make the chat font so we need to create it XMLAttributes xmlAttributes;

// CEGUIFont.cpp xmlAttributes.add("Name", pFontName); xmlAttributes.add("Filename", pFileName); xmlAttributes.add("ResourceGroup", ""); xmlAttributes.add("AutoScaled", "true"); xmlAttributes.add("NativeHorzRes", "800"); xmlAttributes.add("NativeVertRes", "600");

// CEGUIXMLAttributes.cpp xmlAttributes.add("Size", pSize); xmlAttributes.add("AntiAlias", "true");

font = FontManager::getSingleton().createFont("FreeType", xmlAttributes); } font->load(); } catch(Exception& e) { // Display the error message in the chat window addChatText(e.getMessage()); font = 0; }

return font; }

void changeFont(const CEGUI::String& pFontLogicalName, const CEGUI::String& pFontSize) { using namespace CEGUI; WindowManager& winMgr = WindowManager::getSingleton();

if(!FontManager::getSingleton().isFontPresent(mChatFontName)) { addChatText("You must call registerFont() at least once with a valid font"); return; }

FontList::iterator itFontList = mFontList.find(pFontLogicalName); if(itFontList == mFontList.end()) { addChatText(pFontLogicalName + " has not been registered"); return; }

// Measure the height of the selected font Font* currentFont = makeFont(mChatFontName, (*itFontList).second, pFontSize); float fontHeight = currentFont->getFontHeight();

/* Alter the area of the Editbox. The original value is {{0.01,0},{1,-30},{0.99,0},{1,-5}} The value we are altering is the "-30" within the second couplet, defining the position of the upper y coordinate of the Editbox. We base the new value on the position of the lower y coordinate, which is "-5", and the height of the font. To this we add some space "10" to account for the Editbox's border. */ Editbox* editBox = static_cast<Editbox*> (winMgr.getWindow("/ChatBox/Text")); URect chatTextArea = editBox->getArea(); chatTextArea.d_min.d_y.d_offset = chatTextArea.d_max.d_y.d_offset - fontHeight - 10; editBox->setArea(chatTextArea); editBox->setFont(currentFont);

/* Alther the area of the Listbox. Here we only need the lower y coordinate. Since this value is the same as the upper y coordinate of the Editbox we do not need to calculate it. We also change the font of the Listbox and call upon handleUpdatedItemData() to update the current Listbox items. Finally we ensure that the last entry is still visible. */ Listbox* listBox = static_cast<Listbox*> (winMgr.getWindow("/ChatBox/List")); URect listTextArea = listBox->getArea(); listTextArea.d_max.d_y.d_offset = chatTextArea.d_min.d_y.d_offset; listBox->setArea(listTextArea); listBox->setFont(currentFont); listBox->handleUpdatedItemData(); size_t itemCount = listBox->getItemCount(); if(itemCount) { ListboxItem* currentItem = listBox->getListboxItemFromIndex(itemCount - 1); listBox->ensureItemIsVisible(currentItem); } }

private: // Type of list for registered fonts typedef std::map<CEGUI::String, CEGUI::String> FontList;

// List of registered fonts FontList mFontList;

// Maximal number of entries to retain within the Listbox size_t mHistorySize;

// Logical font name dedicated to the chat box // This allows us to modify the properties of that font and not affect the fonts used elsewhere CEGUI::String mChatFontName;

// Default font size CEGUI::String mDefaultFontSize; };

1. endif // _ChatBox_h_

Main.cpp

<cpp/>

1. if defined( __WIN32__ ) || defined( _WIN32 )

#define WIN32_LEAN_AND_MEAN #define NOMINMAX #include "windows.h"

1. endif

1. include "ChatBox_demo.h"

1. if defined( __WIN32__ ) || defined( _WIN32 )

int APIENTRY WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine,int nCmdShow)

1. else

int main(int argc, char *argv[])

1. endif

{

   DemoSample app;
   int i = app.run();
   return i;

}

ChatBox.layout

<?xml version="1.0" encoding="UTF-8"?>

<GUILayout >
    <Window Type="DefaultWindow" Name="Root" >
        <Property Name="InheritsAlpha" Value="False" />
        <Property Name="UnifiedMaxSize" Value="{{1,0},{1,0}}" />
        <Property Name="UnifiedAreaRect" Value="{{0,0},{0,0},{1,0},{1,0}}" />
        <Window Type="TaharezLook/FrameWindow" Name="/ChatBox" >
            <Property Name="Text" Value="Chat" />
            <Property Name="TitlebarFont" Value="Commonwealth-10" />
            <Property Name="InheritsAlpha" Value="False" />
            <Property Name="UnifiedMaxSize" Value="{{1,0},{1,0}}" />
            <Property Name="TitlebarEnabled" Value="True" />
            <Property Name="UnifiedAreaRect" Value="{{0.01,0},{0.03,0},{0.6,0},{0.69375,0}}" />
            <Window Type="TaharezLook/Listbox" Name="/ChatBox/List" >
                <Property Name="UnifiedMaxSize" Value="{{1,0},{1,0}}" />
                <Property Name="UnifiedAreaRect" Value="{{0.02,0},{0.078,0},{0.98,0},{1,-30}}" />
            </Window>
            <Window Type="TaharezLook/Editbox" Name="/ChatBox/Text" >
                <Property Name="Text" Value="Error: you did not register any font or none were valid" />
                <Property Name="MaxTextLength" Value="1073741823" />
                <Property Name="UnifiedMaxSize" Value="{{1,0},{1,0}}" />
                <Property Name="UnifiedAreaRect" Value="{{0.02,0},{1,-30},{0.98,0},{1,-5}}" />
            </Window>
        </Window>
        <Window Type="TaharezLook/Editbox" Name="/ChatBox/History" >
            <Property Name="Text" Value="5" />
            <Property Name="MaxTextLength" Value="1073741823" />
            <Property Name="UnifiedMaxSize" Value="{{1,0},{1,0}}" />
            <Property Name="UnifiedAreaRect" Value="{{0.77,0},{0.03,0},{0.81,0},{0.1,0}}" />
        </Window>
        <Window Type="TaharezLook/StaticText" Name="/ChatBox/HistoryLabel" >
            <Property Name="Text" Value="History size:" />
            <Property Name="HorzFormatting" Value="RightAligned" />
            <Property Name="UnifiedMaxSize" Value="{{1,0},{1,0}}" />
            <Property Name="UnifiedAreaRect" Value="{{0.65,0},{0.03,0},{0.77,0},{0.1,0}}" />
        </Window>
        <Window Type="TaharezLook/StaticText" Name="/ChatBox/FonSizeLabel" >
            <Property Name="Font" Value="Commonwealth-10" />
            <Property Name="Text" Value="Font size:" />
            <Property Name="HorzFormatting" Value="RightAligned" />
            <Property Name="UnifiedMaxSize" Value="{{1,0},{1,0}}" />
            <Property Name="UnifiedAreaRect" Value="{{0.65,0},{0.1,0},{0.77,0},{0.17,0}}" />
        </Window>
        <Window Type="TaharezLook/Spinner" Name="/ChatBox/FontSize" >
            <Property Name="Text" Value="10" />
            <Property Name="StepSize" Value="1" />
            <Property Name="CurrentValue" Value="10" />
            <Property Name="MaximumValue" Value="72" />
            <Property Name="MinimumValue" Value="-32768" />
            <Property Name="UnifiedMaxSize" Value="{{1,0},{1,0}}" />
            <Property Name="UnifiedAreaRect" Value="{{0.77,0},{0.1,0},{0.83,0},{0.17,0}}" />
        </Window>
        <Window Type="TaharezLook/StaticText" Name="/ChatBox/FontNameLabel" >
            <Property Name="Font" Value="Commonwealth-10" />
            <Property Name="Text" Value="Font name:" />
            <Property Name="HorzFormatting" Value="RightAligned" />
            <Property Name="UnifiedMaxSize" Value="{{1,0},{1,0}}" />
            <Property Name="UnifiedAreaRect" Value="{{0.65,0},{0.17,0},{0.77,0},{0.24,0}}" />
        </Window>
        <Window Type="TaharezLook/Combobox" Name="/ChatBox/FontName" >
            <Property Name="Text" Value="ChatBoxFont" />
            <Property Name="ReadOnly" Value="True" />
            <Property Name="UnifiedMaxSize" Value="{{1,0},{1,0}}" />
            <Property Name="UnifiedAreaRect" Value="{{0.77,0},{0.17,0},{0.99,0},{0.45,0}}" />
            <Property Name="MaxEditTextLength" Value="1073741823" />
        </Window>
    </Window>
</GUILayout>