// Numbas version: exam_results_page_options
{"name": "Use canvas to draw a rectangle", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"rulesets": {}, "parts": [{"allowFractions": false, "minValue": "2(w+h)", "type": "numberentry", "maxValue": "2(w+h)", "scripts": {}, "prompt": "<p>What is the rectangle's perimeter, in metres?</p>", "correctAnswerFraction": false, "showCorrectAnswer": true, "marks": 1, "showPrecisionHint": false}, {"allowFractions": false, "minValue": "w*h", "type": "numberentry", "maxValue": "w*h", "scripts": {}, "prompt": "<p>What is the rectangle's area, in metres?</p>", "correctAnswerFraction": false, "showCorrectAnswer": true, "marks": 1, "showPrecisionHint": false}], "ungrouped_variables": ["h", "w"], "name": "Use canvas to draw a rectangle", "variable_groups": [], "variables": {"w": {"name": "w", "description": "", "definition": "random(100..200#5)", "group": "Ungrouped variables", "templateType": "anything"}, "h": {"name": "h", "description": "", "definition": "random(50..100#5)", "group": "Ungrouped variables", "templateType": "anything"}}, "variablesTest": {"maxRuns": 100, "condition": ""}, "metadata": {"licence": "Creative Commons Attribution 4.0 International", "description": "<p>The custom function <code>rectangle(width,height)</code> draws a rectangle with the given dimensions, along with some labels.</p>", "notes": "<p>Doesn't work in IE8, because it doesn't support the canvas element.</p>"}, "tags": ["canvas", "demo", "function", "graphic"], "functions": {"rectangle": {"definition": "\n      var c = document.createElement('canvas');\n        $(c).attr('width',w+40).attr('height',h+40);\n        var context = c.getContext('2d');\n        \n        //fill in rectangle with a light shade\n        context.fillStyle = '#eee';\n        context.fillRect(5,5,w,h);\n        \n        //draw outline\n        context.strokeStyle = '#000';\n        context.lineWidth = 3;\n        context.strokeRect(5,5,w,h);\n        \n        //draw labels\n        context.fillStyle = '#000';\n        context.font = '20px sans-serif';\n        var wstring = w+'m';\n        var tw = context.measureText(wstring).width;\n        console.log(tw);\n        context.fillText(wstring,5+(w-tw)/2,5+h+25);\n        \n        var hstring = h+'m';\n        var hw = context.measureText(hstring).width;\n        context.save();\n        context.translate(5+w+25,5+(h+hw)/2);\n        context.rotate(-Math.PI/2);\n        context.fillText(hstring,0,0);\n        \n        return c;\n      ", "language": "javascript", "type": "html", "parameters": [["w", "number"], ["h", "number"]]}}, "question_groups": [{"pickQuestions": 0, "pickingStrategy": "all-ordered", "questions": [], "name": ""}], "preamble": {"css": "", "js": ""}, "statement": "<p>This rectangle is <strong>{w} metres</strong> wide and <strong>{h} metres</strong> long.</p>\n  <p style=\"text-align: center;\">{rectangle(w,h)}</p>", "showQuestionGroupNames": false, "type": "question", "advice": "", "contributors": [{"name": "Christian Lawson-Perfect", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/7/"}]}]}], "contributors": [{"name": "Christian Lawson-Perfect", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/7/"}]}