javascript - FabricJS TextBox mit fester Größe und dynamischer Schriftgröße (Text an Größe anpassen)
Wie kann ich die Größe eines Textfeldes festlegen und die Schriftgröße dynamisch verkleinern, wenn der Text zu groß für das Textfeld wird? Ja, eine ähnliche Frage existiert hier, aber sie funktioniert nur für eine Textzeile.
Ich möchte genau das erreichen: (Beispiel aus dem imgflip Meme-Editor)
Ich habe den folgenden Ansatz versucht:
let text = new fabric.Textbox(box.text, {
top: box.top,
left: box.left,
width: box.width,
});
if (text.width > box.width) {
text.fontSize *= box.width / (text.width + 1);
text.width = box.width;
}
if (text.height > box.height) {
text.fontSize *= box.height / (text.height + 1);
text.height = box.height;
}
canvas.add(text);
Auf diese Weise verringert sich die Schriftgröße im Verhältnis zur Änderung der Breite oder Höhe des Textfeldes. Aber das führt manchmal dazu, dass der Text extrem klein wird, weil der Text nicht so schön umbrochen wird, wie er könnte. Die Schriftgröße und der Umbruch müssen irgendwie ein Optimum finden. Irgendwelche Ideen? Danke!
Antwort #1
Ich habe tatsächlich eine Lösung gefunden. Nur für den Fall, dass jemand dasselbe Problem hat.
Das Anpassen der Schriftgröße an die Breite funktioniert gut mit meinem ursprünglichen Code:
if (text.width > box.width) {
text.fontSize *= box.width / (text.width + 1);
text.width = box.width;
}
Dies wird die Schriftgröße nur für wirklich lange Wörter anpassen, da die Textbox den Text automatisch umbricht. Aber dieser Umbruch verursacht, dass die Höhe mit meinem ursprünglichen Code zu stark schrumpft. Um den Umbruch zu berücksichtigen, habe ich schließlich die Schriftgröße schrittweise verringert und den Textumbruch neu berechnet, indem ich jedes Mal canvas.renderAll() aufgerufen habe:
while (text.height > box.height && text.fontSize > 12) {
text.fontSize--;
canvas.renderAll();
}
Dies könnte ineffizient sein, aber es erfüllte meinen Anwendungsfall.
Antwort #2
Textumbruch funktioniert und die Schriftgröße ändert sich in Bezug auf die Breite und Höhe des Haftnotizzettels. Der Bearbeitungsmodus wird durch Doppelklick aktiviert.
export const createStickyNotes = (canvas, options) => {
fabric.StickyNote = fabric.util.createClass(fabric.Group, {
type: "StickyNote",
initialize: function (options) {
this.set(options);
var height = this.height;
var width = this.width;
this.rectObj = new fabric.Rect({
width: width,
height: height,
fill: this.rectObj?.fill ?? "rgba(251,201,112,1)",
originX: "center",
originY: "center",
objectCaching: false,
stateProperties: ["fill"],
});
this.textObj = new fabric.Textbox(this.textObj?.text ?? "Notes", {
originX: "center",
originY: "center",
textAlign: "center",
width: 100,
hasControls: false,
fontSize: this.textObj?.fontSize ?? 30,
lineHeight: 1,
stateProperties: ["text", "fontSize"],
scaleX: this.textObj?.scaleX ?? 1,
scaleY: this.textObj?.scaleY ?? 1,
objectCaching: false,
breakWords: true,
fontFamily: "Open Sans",
});
this._objects = [this.rectObj, this.textObj];
// this custom _set function will set custom properties value to object when it will load from json.
// at that time loadFromJson function will call this initialize function.
// this._setCustomProperties(this.options);
canvas.renderAll();
//evenet will fire if the object is double clicked by mouse
this.on("mousedblclick", (e) => {
var pasteFlag = false;
var scaling = e.target.getScaledWidth() / 100;
var textForEditing;
canvas.bringToFront(e.target);
e.target.selectable = false;
const [rectObj, textObj] = this.getObjects();
textObj.clone(function (clonedObj) {
clonedObj.set({
left: e.target.left,
top: e.target.top,
lockMovementY: true,
lockMovementX: true,
hasBorders: false,
scaleX: scaling,
scaleY: scaling,
breakWords: true,
width: textObj.width,
stateProperties: [],
});
textForEditing = clonedObj;
});
this.remove(textObj);
canvas.add(textForEditing);
canvas.setActiveObject(textForEditing);
textForEditing.enterEditing();
textForEditing.selectAll();
textForEditing.paste = (function (paste) {
return function (e) {
disableScrolling();
pasteFlag = true;
};
})(textForEditing.paste);
textForEditing.on("changed", function (e) {
var fontSize = textForEditing.fontSize;
var charCount = Math.max(textForEditing._text.length, 1);
var charWR =
(textForEditing.textLines.length * width) / (charCount * fontSize);
if (textForEditing.height < height - 15) {
fontSize = Math.min(
Math.sqrt(
((height - 10 - fontSize) / 1.16) *
(width / (charCount * charWR))
),
30
);
}
if (textForEditing.height > height - 15) {
fontSize = Math.sqrt(
((height - 10) / 1.16) * (width / (charCount * charWR))
);
}
if (pasteFlag) {
pasteFlag = false;
while (
textForEditing.height > height - 15 &&
textForEditing.fontSize > 0
) {
fontSize = textForEditing.fontSize -= 0.2;
canvas.renderAll();
}
}
textForEditing.fontSize = fontSize;
});
textForEditing.on("editing:exited", () => {
enableScrolling();
canvas.setActiveObject(textObj);
textObj.set({
text: textForEditing.text,
fontSize: textForEditing.fontSize,
visible: true,
});
this.add(textObj);
this.selectable = true;
canvas.remove(textForEditing);
canvas.discardActiveObject();
});
});
function disableScrolling() {
var x = window.scrollX;
var y = window.scrollY;
window.onscroll = function () {
window.scrollTo(x, y);
};
}
var _wrapLine = function (_line, lineIndex, desiredWidth, reservedSpace) {
var lineWidth = 0,
splitByGrapheme = this.splitByGrapheme,
graphemeLines = [],
line = [],
// spaces in different languges?
words = splitByGrapheme
? fabric.util.string.graphemeSplit(_line)
: _line.split(this._wordJoiners),
word = "",
offset = 0,
infix = splitByGrapheme ? "" : " ",
wordWidth = 0,
infixWidth = 0,
largestWordWidth = 0,
lineJustStarted = true,
additionalSpace = splitByGrapheme ? 0 : this._getWidthOfCharSpacing();
reservedSpace = reservedSpace || 0;
desiredWidth -= reservedSpace;
for (var i = 0; i < words.length; i++) {
// i would avoid resplitting the graphemes
word = fabric.util.string.graphemeSplit(words[i]);
wordWidth = this._measureWord(word, lineIndex, offset);
offset += word.length;
// Break the line if a word is wider than the set width
if (this.breakWords && wordWidth >= desiredWidth) {
if (!lineJustStarted) {
graphemeLines.push(line);
line = [];
lineWidth = 0;
lineJustStarted = true;
}
this.fontSize *= desiredWidth / (wordWidth + 1);
// Loop through each character in word
for (var w = 0; w < word.length; w++) {
var letter = word[w];
var letterWidth =
(this.getMeasuringContext().measureText(letter).width *
this.fontSize) /
this.CACHE_FONT_SIZE;
line.push(letter);
lineWidth += letterWidth;
}
word = [];
} else {
lineWidth += infixWidth + wordWidth - additionalSpace;
}
if (lineWidth >= desiredWidth && !lineJustStarted) {
graphemeLines.push(line);
line = [];
lineWidth = wordWidth;
lineJustStarted = true;
} else {
lineWidth += additionalSpace;
}
if (!lineJustStarted) {
line.push(infix);
}
line = line.concat(word);
infixWidth = this._measureWord([infix], lineIndex, offset);
offset++;
lineJustStarted = false;
// keep track of largest word
if (wordWidth > largestWordWidth && !this.breakWords) {
largestWordWidth = wordWidth;
}
}
i && graphemeLines.push(line);
if (largestWordWidth + reservedSpace > this.dynamicMinWidth) {
this.dynamicMinWidth =
largestWordWidth - additionalSpace + reservedSpace;
}
return graphemeLines;
};
fabric.util.object.extend(fabric.Textbox.prototype, {
_wrapLine: _wrapLine,
});
function enableScrolling() {
window.onscroll = function () {};
}
},
toObject: function (propertiesToInclude) {
// This function is used for serialize this object. (used for create json)
// not inlclude this.textObj and this.rectObj into json because when object will load from json, init fucntion of this class is called and it will assign this two object textObj and rectObj again.
var obj = this.callSuper(
"toObject",
[
"objectCaching",
"textObj",
"rectObj",
// ... property list that you want to add into json when this object is convert into json using toJSON() function. (serialize)
].concat(propertiesToInclude)
);
// delete objects array from json because then object load from json, Init function will call. which will automatically re-assign object and assign _object array.
delete obj.objects;
return obj;
},
});
fabric.StickyNote.async = true;
fabric.StickyNote.fromObject = function (object, callback) {
// This function is used for deserialize json and convert object json into button object again. (called when we call loadFromJson() fucntion on canvas)
return fabric.Object._fromObject("StickyNote", object, callback);
};
return new fabric.StickyNote(options);
};//How to use
var options = {
width: 100,
height: 100,
originX: "center",
originY: "center",
};
var notes = StickyNotes(canvas, options);
canvas.add(notes);