<snapdata remixID="8923121"><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><sprite name="Sprite" idx="1" x="199.99999999999957" y="140" heading="90" scale="1" volume="100" pan="0" rotation="1" draggable="true" costume="0" color="255,47,31,1" 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="221" y="254"><block s="receiveGo"></block><block s="clear"></block><custom-block s="Draw checkerboard"></custom-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><block-definition s="Draw checkerboard" type="command" category="pen"><header></header><code></code><translations></translations><inputs></inputs><script><block s="gotoXY"><l>-200</l><l>-140</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>-200</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>-200</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>-200</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>-200</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>-200</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>-200</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>-200</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></script></block-definition></blocks><variables></variables></project><media name="U2L4-checkerboard_SV" app="Snap! 5.1, http://snap.berkeley.edu" version="1"></media></snapdata>