如何在鼠標釋放時在Openlayers中完成徒手繪製

Question

我想在釋放鼠標按鈕而不是雙擊時完成繪製。我怎樣才能做到這一點？

現在，我使用此代碼，默認情況下激活的OpenLayers drawing feature徒手畫：

draw = new ol.interaction.Draw({ 
    source: drawLayerSource, 
    type: 'LineString', 
    condition: ol.events.condition.singleClick, 
    freehandCondition: ol.events.condition.noModifierKeys 
}); 
map.addInteraction(draw); 

但我不知道如何避免雙擊完成線串，並使用鼠標釋放來代替。

Answer 1

UPDATE - https://jsfiddle.net/jonataswalker/frwfuzzn/

要同時啓用寫意直線，我計算抽選開始和pointerup使用此功能之間所經過的時間：

var isStraightLine = function(){ 
    var now = new Date(); 
    // `start_time` was set at the drawing beginning 
    var diff = now - start_time; 
    // strip the ms 
    diff /= 1000; 
    already_checked = true; 
    // an average time I found here 
    // not sure if this is completely reliable 
    return diff < 0.07; 
}; 

如果我發現這是寫意畫完成draw.finishDrawing()。爲了理解起見，更好地檢查代碼。

---

我可以，但只有當你留在freehandCondition默認條件 - ol.events.condition.shiftKeyOnly。

聽pointerupol.Map，如果你正在繪製，完成ol.interaction.Draw#finishDrawing。

var start_drawing = false; 
var draw = new ol.interaction.Draw({ 
    source: vectorSource, 
    type: 'LineString', 
    condition: ol.events.condition.singleClick 
}); 
map.addInteraction(draw); 

draw.on('drawstart', function(evt){ 
    start_drawing = true; 
}); 
draw.on('drawend', function(evt){ 
    start_drawing = false; 
}); 
map.on('pointerup', function(evt){ 
    if(start_drawing) { 
    draw.finishDrawing(); 
    } 
}); 

http://jsfiddle.net/jonataswalker/ewv0mo3c/