<snapdata remixID="8927857"><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="220.00000000000026" y="-135" 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="30" y="49"><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>-180</l><l>-135</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>