<snapdata remixID="8925167"><project name="U2L4-checkerboard_SV" app="Snap! 5.1, http://snap.berkeley.edu" 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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" 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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 var="w" style="normal" x="10" y="10" color="243,118,29" hidden="true"/><sprite name="Sprite" idx="1" x="200" y="-160" heading="90" scale="1" volume="100" pan="0" rotation="1" draggable="true" costume="0" color="255,47,31,1" pen="tip" id="9"><costumes><list struct="atomic" id="10"></list></costumes><sounds><list struct="atomic" id="11"></list></sounds><blocks></blocks><variables></variables><scripts><script x="97" y="131"><custom-block s="checker board"></custom-block></script></scripts></sprite><watcher scope="Sprite" s="xPosition" style="normal" x="0" y="117" color="74,108,212" hidden="true"/><watcher scope="Sprite" s="yPosition" style="normal" x="-32" y="247.000002" color="74,108,212" hidden="true"/></sprites></stage><hidden></hidden><headers></headers><code></code><blocks><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="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>255,56,10,1</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 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