<snapdata remixID="8924944"><project name="U2L4-checkerboard_SV" app="Snap! 5.1, http://snap.berkeley.edu" version="1"><notes></notes><thumbnail>data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAKAAAAB4CAYAAAB1ovlvAAAExklEQVR4Xu3cv29NYRjA8acTJejS0NJKGhExid9TN4liEVJCTA3BQHXVgWiTLsRokoh/A2nvH4AuZgaThcHP5cptbnoi13Ke7805zcm3ia3f+57z9HPfRnruO9But9vhlxOoaQIDAqxp8i67NgEBCqHWCaQAtlaWo9VaKXXhk1s2xeTWzaWazjcvfPlWusms1fr+K1o/fpdea354R+kms1bmntYu7OZs6eurMkgBXHj0MBYfPSh1nfeHd8T88FCppvPNgx8+lW4yay18+RqLCew/D+4tfX2ZtTL3tHZh7z+Wvr4qAwF2p51B0UkFyLgKUIBMEKwFKEBIiOUCFCATBGsBChASYrkABcgEwVqAAoSEWC5AATJBsBagACEhlgtQgEwQrAUoQEiI5SmArcdL0XqyxFa2rmQC85+/VrJOdpEUwHj2NNb+lfhq6t9aN/zDEn829vPGAuy+ibJPmwiwxC70n28VoACZIFgLUICQEMsFKEAmCNYCFCAkxHIBCpAJgrUABQgJsVyAAmSCYC1AAUJCLBegAJkgWAtQgJAQywUoQCYI1imAnoxQTN0PpjOBAuzOr6lP63g0R9N/xXk2DNoC3QHdAREgGgtQgNQQ6gUoQASIxgIUIDWEegEKEAGisQAFSA2hXoACRIBoLEABUkOoF6AAESAaC1CA1BDqUwA9mgPNvNLYozkavsN4MgJ7P6V2QM+GKYYuQAH2TCDzaJVnwzBI2dodsDs5AWYJsU6AAmSCYC1AAUJCLBegAJkgWAtQgJAQywUoQCYI1gIUICTEcgEKkAmCtQAFCAmxPAXQhxHY0KusG/kwgkdzFIQ8moO9nVI7oAAFyNgVtQC7s8g8wNBJ3QEZRQEKkAmCtQAFCAmxXIACZIJgLUABQkIsF6AAmSBYC1CAkBDLBShAJgjWAhQgJMRyAQqQCYK1AAUICbE8BdAPphdD94PpAuyZQObvun4umEHK1u6A3ckJMEuIdQIUIBMEawEKEBJiuQAFyATBWoAChIRYLkABMkGwFqAAISGWC1CATBCsBShASIjlAhQgEwRrAQoQEmJ5CqBHc7ChV1l7NEfTd5iDe0t7qvJhiXj/sfT1VRmkdkCP5ih+RJ6MwLgKsDu/zK7USQUowJ4JZB6tEiCDlK3dAd0Bs3b60glQgH2BlH0RAQowa6cvnQAF2BdI2RcRoACzdvrSCVCAfYGUfREBCjBrpy+dAAXYF0jZF0kB9GGE7Lir7xr5MIJHcxSQPJqDvalSO6AABcjYFbUAu7PI/P24k7oDMooCFCATBGsBChASYrkABcgEwVqAAoSEWC5AATJBsBagACEhlgtQgEwQrAUoQEiI5QIUIBMEawEKEBJieQ4gW9PaCaxPQIBiqHUCAqx1/C4uQA3UOoF/AK4sL8fFC+fj7uxsjIzuiZmZmVovzsWbP4GeHfDN61dxdurU+p3v238gLk1fjiPHjsfU1FTzJ+IdVjqB//4KvnF9Jl6+eN5zIe12xOkz5+LK1WsxPT1d6YW6WDMn0ANwdXU1Thw9FAMDxQ1v2z4Ud+7cjZHdY/5abqaD2u6qB+DJ44fj3dt3cfPW7di5azTuzc3F4OBgbRfows2eQM9/QsbGx2NiYqLZd+3dbZgJ/AVPNUo+kyAr6AAAAABJRU5ErkJggg==</thumbnail><stage name="Stage" width="480" height="360" costume="0" color="255,255,255,1" tempo="60" threadsafe="false" volume="100" pan="0" lines="flat" ternary="true" codify="false" inheritance="false" sublistIDs="false" scheduled="false" id="1"><pentrails>data:image/png;base64,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</pentrails><costumes><list struct="atomic" id="2"></list></costumes><sounds><list struct="atomic" id="3"></list></sounds><variables></variables><blocks></blocks><scripts></scripts><sprites><sprite name="Sprite" idx="1" x="-200" y="-170" heading="90" scale="1" volume="100" pan="0" rotation="1" draggable="true" costume="0" color="8,5,0,1" pen="tip" id="8"><costumes><list struct="atomic" id="9"></list></costumes><sounds><list struct="atomic" id="10"></list></sounds><blocks></blocks><variables></variables><scripts><script x="131" y="157"><block s="clear"></block><block s="gotoXY"><l>-200</l><l>150</l></block><block s="doSetVar"><l>old x coordinate</l><block s="xPosition"></block></block><block s="doRepeat"><l>4</l><script><block s="doRepeat"><l>4</l><script><custom-block s="draw black square size %n"><l>40</l></custom-block><custom-block s="draw red square size %n"><l>40</l></custom-block></script></block><block s="gotoXY"><block var="old x coordinate"/><block s="reportDifference"><block s="yPosition"></block><l>40</l></block></block><block s="doRepeat"><l>4</l><script><custom-block s="draw red square size %n"><l>40</l></custom-block><custom-block s="draw black square size %n"><l>40</l></custom-block></script></block><block s="gotoXY"><block var="old x coordinate"/><block s="reportDifference"><block s="yPosition"></block><l>40</l></block></block></script></block></script></scripts></sprite></sprites></stage><hidden></hidden><headers></headers><code></code><blocks><block-definition s="set flag %&apos;which&apos; to %&apos;tf&apos;" type="command" category="sensing"><header></header><code></code><translations></translations><inputs><input type="%s" readonly="true"><options>Presentation mode&#xD;Retina display support&#xD;Long form input dialog&#xD;Plain prototype labels&#xD;Input sliders&#xD;Execute on slider change&#xD;Clicking sound&#xD;Turbo mode&#xD;Flat design&#xD;Keyboard editing&#xD;Table support&#xD;Table lines&#xD;Visible stepping&#xD;Thread safe scripts&#xD;Prefer smooth animations&#xD;Flat line ends&#xD;Codification support&#xD;Inheritance support</options></input><input type="%b"></input></inputs><script><block s="doRun"><block s="reportJSFunction"><list><l>which</l><l>tf</l></list><l>var   stage = this.parentThatIsA(StageMorph),&#xD;        ide = stage.parentThatIsA(IDE_Morph),&#xD;        world = stage.parentThatIsA(WorldMorph);&#xD;&#xD;if (tf != !!tf) return;&#xD;&#xD;try{&#xD;ide.savingPreferences = false;&#xD;&#xD;switch (which) {&#xD;    case &apos;Presentation mode&apos;:&#xD;        if (tf != ide.isAppMode) ide.toggleAppMode();&#xD;        break;&#xD;    case &apos;Retina display support&apos;:&#xD;        if (tf != isRetinaEnabled()) ide.toggleRetina();&#xD;        break;&#xD;    case &apos;Long form input dialog&apos;:&#xD;        if (tf != InputSlotDialogMorph.prototype.isLaunchingExpanded)&#xD;            ide.toggleLongFormInputDialog();&#xD;        break;&#xD;    case &apos;Plain prototype labels&apos;:&#xD;        if (tf != BlockLabelPlaceHolderMorph.prototype.plainLabel)&#xD;            ide.togglePlainPrototypeLabels();&#xD;        break;&#xD;    case &apos;Input sliders&apos;:&#xD;        MorphicPreferences.useSliderForInput = tf;&#xD;        break;&#xD;    case &apos;Execute on slider change&apos;:&#xD;        ArgMorph.prototype.executeOnSliderEdit = tf;&#xD;        break;&#xD;    case &apos;Clicking sound&apos;:&#xD;        if (tf != !!BlockMorph.prototype.snapSound)&#xD;            BlockMorph.prototype.toggleSnapSound();&#xD;        break;&#xD;    case &apos;Turbo mode&apos;:&#xD;        if (tf != stage.isFastTracked)&#xD;            ide.toggleFastTracking();&#xD;        break;&#xD;    case &apos;Flat design&apos;:&#xD;        if (tf == MorphicPreferences.isFlat) break;&#xD;        if (tf)&#xD;            ide.flatDesign();&#xD;        else&#xD;            ide.defaultDesign();&#xD;        break;&#xD;    case &apos;Keyboard editing&apos;:&#xD;            ScriptsMorph.prototype.enableKeyboard = tf;&#xD;        break;&#xD;    case &apos;Table support&apos;:&#xD;            List.prototype.enableTables = tf;&#xD;        break;&#xD;    case &apos;Table lines&apos;:&#xD;                TableMorph.prototype.highContrast = tf;&#xD;        break;&#xD;    case &apos;Visible stepping&apos;:&#xD;        if (tf != Process.prototype.enableSingleStepping)&#xD;            ide.toggleSingleStepping();&#xD;        break;&#xD;    case &apos;Thread safe scripts&apos;:&#xD;        stage.isThreadSafe = tf;&#xD;        break;&#xD;    case &apos;Prefer smooth animations&apos;:&#xD;        if (tf != (StageMorph.prototype.frameRate &gt; 0))&#xD;            ide.toggleVariableFrameRate();&#xD;        break;&#xD;    case &apos;Flat line ends&apos;:&#xD;        SpriteMorph.prototype.useFlatLineEnds = tf;&#xD;        break;&#xD;    case &apos;Codification support&apos;:&#xD;        if (tf != StageMorph.prototype.enableCodeMapping) {&#xD;            StageMorph.prototype.enableCodeMapping = tf;&#xD;            ide.currentSprite.blocksCache.variables = null;&#xD;            ide.currentSprite.paletteCache.variables = null;&#xD;            ide.refreshPalette();&#xD;        }&#xD;        break;&#xD;    case &apos;Inheritance support&apos;:&#xD;        if (tf != StageMorph.prototype.enableInheritance) {&#xD;            StageMorph.prototype.enableInheritance = tf;&#xD;            ide.currentSprite.blocksCache.variables = null;&#xD;            ide.currentSprite.paletteCache.variables = null;&#xD;            ide.refreshPalette();&#xD;        }&#xD;        break;&#xD;};&#xD;}&#xD;finally {&#xD;ide.savingPreferences = false;&#xD;};&#xD;</l></block><list><block var="which"/><block var="tf"/></list></block></script></block-definition><block-definition s="draw brick, length: %&apos;length&apos; width: %&apos;width&apos;" type="command" category="pen"><header></header><code></code><translations></translations><inputs><input type="%n"></input><input type="%n"></input></inputs><script><block s="setColor"><color>145,26,68,1</color></block><custom-block s="set flat line ends to %b"><block s="reportBoolean"><l><bool>true</bool></l></block></custom-block><block s="setSize"><block var="width"/></block><block s="down"></block><block s="forward"><block var="length"/></block><block s="up"></block></script></block-definition><block-definition s="set flat line ends to %&apos;flag&apos;" type="command" category="pen"><header></header><code></code><translations></translations><inputs><input type="%b"></input></inputs><script><custom-block s="set flag %s to %b"><l>Flat line ends</l><block var="flag"/></custom-block></script></block-definition><block-definition s="draw black square size %&apos;size&apos;" type="command" category="pen"><header></header><code></code><translations></translations><inputs><input type="%n"></input></inputs><script><block s="setColor"><color>8,5,0,1</color></block><custom-block s="set flat line ends to %b"><block s="reportBoolean"><l><bool>true</bool></l></block></custom-block><block s="setSize"><block var="size"/></block><block s="down"></block><block s="forward"><block var="size"/></block><block s="up"></block></script></block-definition><block-definition s="draw red square size %&apos;size&apos;" type="command" category="pen"><header></header><code></code><translations></translations><inputs><input type="%n"></input></inputs><script><block s="setColor"><color>255,47,31,1</color></block><custom-block s="set flat line ends to %b"><block s="reportBoolean"><l><bool>true</bool></l></block></custom-block><block s="setSize"><block var="size"/></block><block s="down"></block><block s="forward"><block var="size"/></block><block s="up"></block></script></block-definition></blocks><variables><variable name="old x coordinate"><l>-200</l></variable></variables></project><media name="U2L4-checkerboard_SV" app="Snap! 5.1, http://snap.berkeley.edu" version="1"></media></snapdata>