<snapdata remixID="8927425"><project name="U2L4-checkerboard_SV" app="Snap! 5.1, http://snap.berkeley.edu" version="1"><notes></notes><thumbnail>data:image/png;base64,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</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><watcher scope="Sprite" s="xPosition" style="normal" x="10" y="10" color="74,108,212"/><watcher scope="Sprite" s="yPosition" style="normal" x="10" y="31.000001999999995" color="74,108,212"/><sprite name="Sprite" idx="1" x="-178" y="140" heading="90" scale="1" volume="100" pan="0" rotation="1" draggable="true" costume="0" color="255,47,31,1" pen="tip" id="10"><costumes><list struct="atomic" id="11"></list></costumes><sounds><list struct="atomic" id="12"></list></sounds><blocks></blocks><variables></variables><scripts><script x="23" y="10"><block s="clear"></block></script><script x="72.999999" y="98.99999899999995"><block s="gotoXY"><l>-178</l><l>-140</l></block><block s="doRepeat"><l>5</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"><l>-178</l><l>-100</l></block><block s="doRepeat"><l>5</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"><l>-178</l><l>-60</l></block><block s="doRepeat"><l>5</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"><l>-178</l><l>-20</l></block><block s="doRepeat"><l>5</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"><l>-178</l><l>20</l></block><block s="doRepeat"><l>5</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"><l>-178</l><l>60</l></block><block s="doRepeat"><l>5</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"><l>-178</l><l>100</l></block><block s="doRepeat"><l>5</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"><l>-178</l><l>140</l></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></variables></project><media name="U2L4-checkerboard_SV" app="Snap! 5.1, http://snap.berkeley.edu" version="1"></media></snapdata>