1 // Copyright (C) 2019 The Android Open Source Project 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 export function cropText(str: string, charWidth: number, rectWidth: number) { 16 const maxTextWidth = rectWidth - 4; 17 let displayText = ''; 18 const nameLength = str.length * charWidth; 19 if (nameLength < maxTextWidth) { 20 displayText = str; 21 } else { 22 // -3 for the 3 ellipsis. 23 const displayedChars = Math.floor(maxTextWidth / charWidth) - 3; 24 if (displayedChars > 3) { 25 displayText = str.substring(0, displayedChars) + '...'; 26 } 27 } 28 return displayText; 29 } 30 31 export function drawDoubleHeadedArrow( 32 ctx: CanvasRenderingContext2D, 33 x: number, 34 y: number, 35 length: number, 36 showArrowHeads: boolean, 37 width = 2, 38 color = 'black') { 39 ctx.beginPath(); 40 ctx.lineWidth = width; 41 ctx.lineCap = 'round'; 42 ctx.strokeStyle = color; 43 ctx.moveTo(x, y); 44 ctx.lineTo(x + length, y); 45 ctx.stroke(); 46 ctx.closePath(); 47 // Arrowheads on the each end of the line. 48 if (showArrowHeads) { 49 ctx.beginPath(); 50 ctx.moveTo(x + length - 8, y - 4); 51 ctx.lineTo(x + length, y); 52 ctx.lineTo(x + length - 8, y + 4); 53 ctx.stroke(); 54 ctx.closePath(); 55 ctx.beginPath(); 56 ctx.moveTo(x + 8, y - 4); 57 ctx.lineTo(x, y); 58 ctx.lineTo(x + 8, y + 4); 59 ctx.stroke(); 60 ctx.closePath(); 61 } 62 }
