SWT 合成/画布适合图像答案

【问题标题】：SWT Composit/Canvas Fit ImageSWT 合成/画布适合图像
【发布时间】：2020-10-24 16:25:52
【问题描述】：

我正在尝试使图像适合可随窗口调整大小的复合材料（或画布）。当它出现时，我想确保它不会弄乱纵横比，所以我编写了这段代码来覆盖打印功能：

      bazaarMenu.addPaintListener(new PaintListener() {
            public void paintControl(PaintEvent event) {
                Image image = SWTResourceManager.getImage(mainFrame.class, "/assets/SkyHub/resources/images/bazaarBackground.jpg");//get the image
                int w = bazaarMenu.getClientArea().width;//composite width
                int h = bazaarMenu.getClientArea().height;//composite height
                int iw = image.getBounds().width;//image width
                int ih = image.getBounds().height;// image height
                
                //these are the values of the width/height of the image if ratio is same with the 
                //composite's
                int w1 = ih * (w / h);
                int h1 = iw * (h / w);
                
                //Find which value can be used and draw the image
                if(w1 <= w)
                {
                    event.gc.drawImage(image, 0, 0, w1, ih, 0, 0, w, h);
                }
                else// if(w / h < 76 / 45)
                {
                    event.gc.drawImage(image, 0, 0, iw, h1, 0, 0, w, h);
                }
            }
       });

但是，我无法得到我想要的结果。可以看到图像拉伸或仅可以看到其中的一部分。有没有其他方法可以做，或者我错过了什么。

【问题讨论】：

标签： java image swt aspect-ratio

【解决方案1】：

已修复，问题是 int 太不准确，如果有人在搜索比率代码，这里是代码：

bazaarMenu.addPaintListener(new PaintListener() {
            @Override
            public void paintControl(PaintEvent event) {
                Image image = SWTResourceManager.getImage(mainFrame.class, "/assets/SkyHub/resources/images/bazaarBackground.jpg");
                float w = bazaarMenu.getClientArea().width;
                float h = bazaarMenu.getClientArea().height;
                float iw = image.getBounds().width;
                float ih = image.getBounds().height;
                float a = 0;
                
                if(w / h > iw / ih)
                {
                    a = ih - (ih * w - iw * h) / w;
                    event.gc.drawImage(image, 0, (int)(ih - a) / 2, (int)iw, (int)a, 0, 0, (int)w, (int)h);
                }
                else
                {
                    a = (w * ih) / h;
                    event.gc.drawImage(image, (int)(iw - a) / 2, 0, (int)a, (int)ih, 0, 0, (int)w, (int)h);
                }
                //event.gc.setFont(new Font( minionButton.getDisplay(), new FontData( "Arial", 10, SWT.BOLD )));
                //event.gc.drawText(" Canvas W: " + w + "\n Canvas H: " + h + "\n Image W: " + iw + "\n Image H: " + ih + "\n a: " + a + "\n Mode: " + ((w / h > iw / ih)? "landscape" : "portrait") + "\n Canvas ratio: " + (w / h) + "\n Image ratio: " + (iw / ih), 5, 5);
            }
        });

【讨论】：